Vascular ablation

ABSTRACT

The disclosure includes a vein ablation system, comprising a catheter having an elongated body. In some embodiments, the vein ablation system comprises an ablation device at a distal portion of the elongated body. According to some embodiments, the vein ablation system comprises a control device at a proximal portion of the elongated body. The control device may comprise an input mechanism configured to simultaneously control at least two of a longitudinal translation of the ablation device through a target vessel, a rotation of the ablation device about a central longitudinal axis, and an infusion of a chemical agent into the target vessel.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 63/163,728, filed 19 Mar. 2021, and entitled“ENDOVASCULAR DEVICES AND METHODS”; U.S. Provisional Patent ApplicationNo. 63/255,385, filed 13 Oct. 2021, and entitled “VEIN ABLATION SYSTEMSAND METHODS”; and U.S. Provisional Patent Application No. 63/270,547,filed 21 Oct. 2021, and entitled “VEIN ABLATION SYSTEMS AND METHODS,”all three of which are incorporated by reference herein in theirentirety.

TECHNICAL FIELD

The present disclosure relates to intravascular medical devices.

BACKGROUND

Sclerotherapy is a medical procedure for treating certain vasculardisorders, such as varicose veins. Current sclerotherapy treatmentsinclude some combination of the following three elements: mechanicallyablating (e.g., disrupting or agitating) an interior surface of a targetvessel with an ablation device; longitudinally (e.g., proximally and/ordistally) translating the ablation device through the target vesselwhile the ablation device is actuated; and infusing a chemical agent(e.g., a sclerosant) into the target vessel.

SUMMARY

Systems and techniques are disclosed herein for treating vasculardisorders, such as varicose veins, through mechanical and/or chemicalablation of a target vessel. As detailed further below, in someexamples, an ablation system includes a catheter having a distalablation device and a proximal control device (e.g., handle) configuredto control the ablation device. In particular, the control deviceincludes one or more user controls (e.g., user-input mechanisms)enabling the user to control at least two different functions of thetreatment simultaneously.

In some examples, a vessel ablation system includes a catheter having anelongated body. In some examples, the vein ablation system comprises anablation device at a distal portion of the elongated body. According tosome examples, the vein ablation system comprises a control device at aproximal portion of the elongated body. The control device may comprisean input mechanism configured to simultaneously control at least two ofa proximal retraction of the ablation device through a target vessel, arotation of the ablation device about a central longitudinal axis, andan infusion of a chemical agent into the target vessel.

In some examples, the input mechanism is configured to simultaneouslycontrol the proximal retraction and the rotation of the ablation device.According to some examples, the vein ablation system further comprises afirst track disposed within a lumen of the elongated body. The veinablation system may further comprise a second track disposed within thelumen of the elongated body. In some examples, the vein ablation systemfurther comprises a worm gear. According to some examples, the veinablation system further comprises a thumb wheel operatively coupled tothe first track, the second track, and the worm gear, the thumb wheelarranged and configured to simultaneously move the first track and thesecond track simultaneously in opposing directions along a firstdirection, and rotate the ablation device about the first direction viathe worm gear.

The elongated body may define a fluid infusion lumen and a fluidaspiration, the control device arranged and configured to remove bloodfrom the target vessel via the fluid aspiration lumen while the ablationdevice delivers the chemical agent to the target vessel via the fluidinfusion lumen.

In some examples, the ablation device comprises at least one ablatingwire configured to contact an interior surface of the target vessel.According to some examples, the at least one ablating wire is arrangedand configured to mechanically ablate the target vessel by piercing theinterior surface of the target vessel. The distal portion of the atleast one ablating wire may comprise a spherical tip. In some examples,the at least one ablating wire is arranged and configured to deliver thechemical agent to the target vessel.

According to some examples, the chemical agent comprises a sclerosant.The vein ablation system may further comprise a foaming agent cartridgedetachably coupled to the control device, the foaming agent cartridgearranged and configured to release a foaming agent to create a foam whenmixed with the sclerosant.

In some examples, the vein ablation system further comprises acontinuous-feed tube operatively coupled to a piston configured toconcurrently proximally retract the ablation device and infuse thechemical agent. According to some examples, the control device comprisesmeans for enabling a user to control a rate of infusion of the chemicalagent relative to a distance of proximal retraction of the ablationdevice. The chemical agent may comprise a cryoablation agent.

In some examples, the vein ablation system further comprises a motorconfigured to proximally retract the ablation device and to deliver thechemical agent via a fluid infusion lumen of the elongated body.According to some examples, the control device further comprises adistance display configured to indicate a distance between the controldevice and the ablation device.

The vein ablation system may further comprise an expandable memberdisposed at the distal portion of the elongated body. In some examples,the control device is configured to cause the expandable member toexpand radially outward by infusing the chemical agent. According tosome examples, the expandable member defines a plurality of poresconfigured to release the chemical agent. The control device maycomprise a reusable control device, and wherein the elongated body andthe ablation device are removably coupled to the control device.

In some examples, the elongated body defines a guidewire lumen, a fluidinfusion lumen, and a fluid aspiration lumen.

According to some examples, the ablation device comprises a plurality ofelongated tines configured to expand radially outward to contact theinterior surface of the target vessel. The elongated tines may extendgenerally parallel to a central longitudinal axis of the elongated body.In some examples, the elongated tines twist helically about an internalaxis of the elongated tines. According to some examples, the elongatedtines extend generally helically about the distal portion of theelongated body.

The vein ablation system may further comprise a distal stopperconfigured to retain the chemical agent within the target vessel. Insome examples, the distal stopper comprises a nickel-titanium skirt andshroud.

According to some examples, the ablation device comprises a plurality ofelongated microtubes each defining at least one pore configured torelease the chemical agent. Each elongated microtube may furthercomprise a shape-memory coil configured to expand the microtube to apredetermined configuration. In some examples, each elongated microtubedefines a plurality of pores along an exterior surface of the microtube.According to some examples, each elongated microtube defines one porenear a distalmost end of the microtube.

The ablation device may comprise a plurality of vein-scratchersconfigured to self-expand radially outward to contact the interiorsurface of the target vessel. In some examples, the vein ablation systemfurther comprises an Archimedes screw disposed within a lumen of theelongated body, the Archimedes screw configured to distally pump thechemical agent toward the target vessel. According to some examples, thevein ablation system further comprises a pulley system configured totranslate a rotational motion of a motor of the control device into aproximal linear motion of the ablation device.

The control device may comprise a slider configured to proximallyretract the ablation device. In some examples, the slider comprises acurved trigger. According to some examples, the slider comprises aheart-shaped pullback mechanism.

The control device may be configured to cause the proximal portion ofthe elongated body to coil within the control device as the controldevice causes the ablation device to proximally retract. In someexamples, the control device is configured to release the chemical agentretained within the proximal portion of the elongated body as theelongated body coils within the control device.

According to some examples, the elongated body comprises a plurality ofwings configured to extend radially outward to contact the interiorsurface of the target vessel. The vein ablation system may furthercomprise a rotating diffuser brush configured to disperse the chemicalagent along the interior surface of the target vessel. In some examples,the vein ablation system further comprises a rotating hypotube offsetfrom the central longitudinal axis, the rotating hypotube configured torelease the chemical agent through a plurality of pores.

According to some examples, the elongated body defines a sinusoidalshape, and wherein the elongated body is configured to rotate about thecentral longitudinal axis. The elongated body may define a plurality ofpores configured to release the chemical agent. In some examples, thevein ablation system further comprises an interventional balloonretaining the sinusoidal elongated body, wherein the sinusoidalelongated body is configured to rotate to infuse the chemical agentthrough a porous membrane of the balloon.

According to some examples, the ablation device comprises a wire loopconfigured to contact the interior surface of the target vessel. Thevein ablation system may further comprise a revolver mechanismconfigured to rotatably engage a plurality of syringes with a fluidinfusion lumen of the elongated body. In some examples, the veinablation system further comprises a weeping roller offset from thecentral longitudinal axis, the weeping roller configured to rotate aboutthe central longitudinal axis and to revolve about a central axis of theroller to infuse the chemical agent. According to some examples, thevein ablation system further comprises a bioabsorbable plug configuredto occlude a distal portion of the target vessel.

The vein ablation system may further comprise a porous balloonconfigured to release the chemical agent. In some examples, the proximalportion of the elongated body comprises an inflatable balloon configuredto form a vacuum to retain the chemical agent within the target vessel.According to some examples, the vein ablation system further comprises aproximal balloon and a distal balloon, the proximal and distal balloonsconfigured to inflate to straighten a portion of the target vesseldisposed between the proximal balloon and the distal balloon. The veinablation system may further comprise a balloon positioned within ashape-memory-material cage configured to cause the balloon toself-expand radially outward.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages are described belowwith reference to the drawings, which are intended to illustrate, butnot to limit, the invention. In the drawings, like reference charactersdenote corresponding features consistently throughout similarembodiments.

FIG. 1 is a conceptual diagram of an ablation system including acatheter having a proximal control device and a distal ablation device.

FIG. 2 is a conceptual diagram illustrating an application of an exampleof the ablation system of FIG. 1 .

FIG. 3 is a conceptual diagram illustrating another example of theablation system of FIG. 1 .

FIGS. 4A-4C are cross-sectional views through three examples of thecatheter of FIG. 1 .

FIG. 5 is a profile view of an example of the ablation device of FIG. 1.

FIG. 6 is a profile view of an example of the ablation device of FIG. 1.

FIG. 7 is a profile view of an example of the ablation device of FIG. 1, including a plurality of fluid microtubes.

FIGS. 8A-8C are side views of three examples of the fluid microtubes ofFIG. 7 .

FIGS. 9A-9D illustrate a technique for using an example of the ablationdevice of FIG. 1 having a self-expanding mechanical agitator.

FIG. 10 illustrates an example ablation device of the ablation system ofFIG. 1 having another self-expanding mechanical agitator.

FIG. 11 is a conceptual diagram illustrating an example gear-and-trackmechanism of the ablation system of FIG. 1 .

FIGS. 12A and 12B are conceptual diagrams illustrating an exampleworm-gear mechanism of the ablation system of FIG. 1 .

FIGS. 13A-13C depict an example dual-coaxial-worm-gear mechanism for theablation system of FIG. 1 .

FIG. 14 is a transparent perspective view of an example of the controldevice of FIG. 1 having an integrated forward-spur-gear mechanism.

FIG. 15 is a transparent perspective view of an example of the controldevice of FIG. 1 having an integrated rear-spur-gear mechanism.

FIG. 16 depicts an example forward pulley mechanism for the ablationsystem of FIG. 1 .

FIGS. 17A and 17B depict an example control device of the ablationsystem of FIG. 1 having a reverse pulley mechanism.

FIGS. 18A-18C illustrate an example straight-syringe catheter of theablation system of FIG. 1 in a retracted configuration.

FIGS. 19A-19C illustrate the straight-syringe catheter of FIGS. 18A-18Cin an advanced configuration.

FIG. 20 is a profile view of an example control device of the ablationsystem of FIG. 1 having a manual slider mechanism.

FIGS. 21A and 21B are profile views of an example control device of theablation system of FIG. 1 having a two-finger pullback mechanism.

FIG. 22 is a conceptual diagram of an example isolated, segmentalmechanical-chemical ablation (ISMA) device of the ablation system ofFIG. 1 .

FIG. 23 is a conceptual diagram of an example control device of theablation system of FIG. 1 having a continuous-feed tube.

FIG. 24 is a conceptual diagram of an example control device of theablation system of FIG. 1 having a coiled feed mechanism.

FIGS. 25A-25C are conceptual diagrams of three examples of the ablationdevice of FIG. 1 having radially expanding wing mechanisms.

FIGS. 26A-26C are conceptual diagrams of three examples of the ablationdevice of FIG. 1 having rotating diffusion brushes.

FIGS. 27A and 27B are conceptual diagrams of two examples of theablation device of FIG. 1 having rotating hypotubes.

FIGS. 28A and 28B are conceptual diagrams of two examples of theablation device of FIG. 1 having rotating sinusoidal mechanisms.

FIGS. 29A and 29B are conceptual diagrams of two examples of theablation device of FIG. 1 having rotating wire-loop mechanisms.

FIG. 30 is a conceptual diagrams of an example control device of theablation system of FIG. 1 having a rotating syringe holder mechanism.

FIGS. 31A-31C are conceptual diagrams of three examples of the ablationdevice of FIG. 1 having weeping roller mechanisms.

FIGS. 32A-32H are conceptual diagrams of eight examples of the ablationdevice of FIG. 1 having bioabsorbable plug mechanisms.

FIGS. 33A-33C are conceptual diagrams of self-expanding vessel occludersfor the ablation system of FIG. 1 .

FIGS. 34A-34F are conceptual diagrams of six examples of the ablationdevice of FIG. 1 having weeping-balloon mechanisms.

FIGS. 35A-35C are conceptual diagrams illustrating functionality of aweeping balloon mechanism for the ablation system of FIG. 1 .

FIGS. 36A-36D are conceptual diagrams of four example interventionalballoons for the ablation system of FIG. 1

FIG. 37 is a conceptual diagram of an example ablation device of FIG. 1having a mechanical agitator configured to be radially expanded by aninterventional balloon.

FIG. 38 is a conceptual diagram of an example of the ablation device ofFIG. 1 having a modular rapid-exchange (RX) platform.

FIGS. 39A and 39B are profile views of an example of the ablation deviceof FIG. 1 having a distal interventional balloon.

FIGS. 40A and 40B are conceptual diagrams of an example of the ablationsystem of FIG. 1 having a distal interventional balloon disposed withina mechanical agitator.

FIGS. 41A-41D illustrate an example of the catheter of FIG. 1 having asteerable distal portion.

FIGS. 42A-42C are conceptual diagrams illustrating a technique for usingtwo interventional balloon elements of an example of the ablation systemof FIG. 1 to straighten a target vessel for subsequent ablation.

FIG. 43 is a conceptual diagram illustrating an example of the ablationdevice of FIG. 1 having a radially biasing balloon.

FIG. 44 is a conceptual diagram illustrating an example of the ablationdevice of FIG. 1 having a self-expanding balloon.

FIGS. 45A-45C are conceptual diagrams illustrating an example stitchingtechnique for ablating a target vessel.

FIG. 46 is a flow diagram illustrating an example technique for ablatinga target vessel of a patient's vasculature.

DETAILED DESCRIPTION Component Index

-   100—Ablation System-   102—Catheter-   104—Introducer Sheath-   106—Elongated Body-   108—Proximal Catheter Portion-   110—Distal Catheter Portion-   112—Proximal Control Device-   114—Distal Ablation Device-   202—Target Vessel-   204—Agitator-   206—Fluid Reservoir-   208—Chemical Agent-   210—Inner Lumen-   212—User Control-   214—Central Longitudinal Axis-   216—Vessel Occluder-   300A—Non-Sterile Environment-   300B—Sterile Environment-   302—Single-Use Catheter-   304—Reusable Control Device-   306—Connection Interface-   308—Agitator Input-   310—Infusion Input-   312—Translation Input-   314—Rate Input(s)-   316—Agitator Driver-   318—Translation Driver-   402—Outer Tube-   404—Middle Tube-   406—Inner Tube-   408—Inner Elongated Member-   410A—Guidewire Lumen-   410B—Fluid-Infusion Lumen-   410C—Fluid-Aspiration Lumen-   504—Straight-Tine Agitator-   506—Elongated Tines-   510—Distal Catheter Mouth-   514—Ablation Device-   604—Spiral-Tine Agitator-   606—Elongated Tines-   608—Spherical Tip-   614—Ablation Device-   706—Fluid Microtubes-   714—Ablation Device-   806A—Shape-Memory Fluid Microtube-   806B—Single-Aperture Fluid Microtube-   806C—Porous Fluid Microtube-   808—Shape-Memory Coil-   810—Fluid Aperture(s)-   902—Agitator Retainer-   904—Self-Expanding Agitator-   906—Elongated Tines-   910—Weeping Balloon-   914—Ablation Device-   1004—Self-Expanding Agitator-   1006—Elongated Tines-   1012—Apertures-   1014—Ablation Device-   1016—Interventional Balloon-   1100—Gear-and-Track Mechanism-   1102—Gear-   1104—Tracks-   1200—Worm-Gear Mechanism-   1202—Worm Gear-   1204—Longitudinal Shaft-   1206—Coiled Thread-   1208—Wheel Gear-   1300—Dual-Worm-Gear Mechanism-   1304A—Outer Shaft-   1304B—Inner Shaft-   1306A—Outer Coiled Thread-   1306B—Inner Coiled Thread-   1308—Thumbwheel-   1402—Forward Spur Gear Mechanism-   1404—Thumbwheel-   1406—Wheel Axis-   1408—Wheel Gear-   1410—Syringe Plunger-   1412—Control Device-   1414—Catheter Rollers-   1502—Rear Spur Gear Mechanism-   1504—Housing Aperture-   1506—Housing-   1508—Syringe Teeth-   1510—Trigger Lock-   1512—Control Device-   1600—Pulley Mechanism-   1602—Motor-   1604—Pulley Wheel-   1612—Control Device-   1700—Reverse Pulley Mechanism-   1704—Housing Aperture-   1706—Housing-   1708—Pulley Wheels-   1710—Knobs-   1712—Control Device-   1802—Straight-Syringe Catheter-   1806—Elongated Body-   1808—Proximal Portion-   1810—Distal Portion-   1812—Control Knob-   1816—Displacement Indicator-   1818—Grip-   1820—Indicator Handle-   1822—Distal Mouth-   2002—Slider-   2002A—Retracted Slider Position-   2002B—Advanced Slider Position-   2006—Housing-   2012—Control Device-   2016—Displacement Indicator-   2022—Distal Mouth-   2102—User Control-   2104—Thumbwheel-   2112—Control Device-   2202A—Proximal Balloon-   2202B—Distal Balloon-   2206—Mechanical Agitator-   2214—Ablation Device-   2302—Continuous Feed Tube-   2304—Piston-   2306—User Control-   2308—Top Portion-   2310—Bottom Portion-   2312—Control Device-   2402—Coiled Feed Tube-   2404—User Control-   2412—Control Device-   2502A—Catheter Wings-   2502B—Catheter Wings-   2502C—Wire Wings-   2504—Wires-   2514—Ablation Device-   2602A-2602C—Brushes-   2614—Ablation Device-   2702A, 2702B—Rotating Hypotubes-   2704—Abrading Surface-   2714—Ablation Device-   2804—Sinusoidal Agitator-   2814—Ablation Device-   2902—Distal Wire Tip-   2904A, 2904B—Wire Agitators-   2914—Ablation Device-   3002—Rotary Syringe Holder-   3004—Syringes-   3006—Y-Hub-   3008—Plunger-   3012—Control Device-   3114—Ablation Device-   3102A-3102C—Weeping Rollers-   3202A-3202H—Bioabsorbable Plugs-   3204—Outer Plug Layer-   3206—Inner Plug Balloon-   3208—Patient-   3210—Access Thread-   3212—Distal Plug Cover-   3214—Securement Stent-   3216—Vessel Occluder-   3218—Delivery Device Tip-   3220—Delivery System-   3222—Coil-   3224—Stent-   3302A-3302C—Self-Expanding Baskets-   3304A—Fabric Layer-   3304B—Shape-Memory-Material Layer-   3306—Atraumatic Distal Tip-   3316—Vessel Occluder-   3402—Shape-Memory-Material Skirt-   3404—Shape-Memory-Material Wings-   3406—Outer Balloon-   3408—Inner Balloon-   3410—Rough-Surfaced Balloon-   3412—Distal Balloon Extension-   3414A-3414F—Ablation Devices-   3416—Brush-   3418—Cheese-Grater Agitator-   3602—Polymer Balloon Layer-   3608—Shape-Memory-Material Basket-   3606—Fabric Balloon Layer-   3608—Balloon Anchors-   3610A-3610D—Weeping Balloons-   3612A, 3612B—Anchoring Balloons-   3614—Central Weeping Section-   3704—Agitator-   3714—Ablation Device-   3802—Modular Rapid-Exchange Platform-   3804—Agitator-   3806—Rapid-Exchange Port-   3808—Pullwire-   3810—Balloon-   3814—Ablation Device-   3902—Fluid-Aspiration Port-   3904—Fluid-Inflation Port-   3910—Weeping Balloon-   3914—Ablation Device-   4000—Ablation System-   4002—Catheter-   4006—Syringe-   4010—Balloon-   4014—Ablation Device-   4016—Elongated Tines-   4022—Aperture-   4110—Steerable Distal Catheter Portion-   4112—Pullwire-   4114—Ablation Device-   4210A, 4210B—Proximal and Distal Balloons-   4310—Radially Eccentric Balloon-   4314—Ablation Device-   4402—Shape-Memory-Material Basket-   4410—Self-Expanding Balloon-   4414—Ablation Device-   4502—Needle-   4514—Ablation Device-   4600, 4602, 4604, 4606, and 4608—Ablation-Technique Steps

The present disclosure describes systems and techniques for treatingvascular disorders, such as varicose veins. Some existing solutionsinclude the use of highly complicated interventional devices (e.g.,ablation catheters) that require excessive dexterity and training tooperate effectively.

For instance, certain sclerotherapeutic catheters require the user(e.g., a clinician) to operate a first manual control (e.g., a syringeplunger) to infuse a chemical agent, such as a sclerosant, into a targetvessel, while simultaneously operating a second, distinct manual controlto longitudinally translate (e.g., distally advance and/or proximallywithdraw) the catheter to disperse the chemical agent throughout thetarget vessel. In some such examples, the secondary control merelyconsists of the clinician manually pushing and/or pulling the catheterthrough the patient's vasculature. Needless to say, such systems are notwidely regarded to be user-friendly.

Furthermore, some vascular treatment devices incorporatemechanical-based ablation devices in addition to, or instead of,chemical-based ablation. In many cases, mechanical ablation improves theeffectiveness of the treatment, but exponentially complicates theoperation of the device by not only incorporating yet another manualcontrol to actuate a motion (e.g., rotation) of a mechanical agitator ofthe ablation device, but also requiring the clinician to consciouslymanage relative rates between all three aspects—i.e., a rate oflongitudinal translation through the vessel, a rate of fluid infusion,and a rate of mechanical agitation.

In other words, many traditional sclerotherapy treatments require theclinician to manually infuse a “steady” flow of sclerosant, manipulate aseparate control (e.g., squeeze a trigger) to actuate an abrasiveelement to mechanically disturb the vessel wall, and also simultaneouslymanually withdraw the catheter at a consistent rate. The requiredcognitive load and skill of the user to simultaneously accomplish all ofthese steps is high, leading to a greater likelihood of mismatching theamount of mechanical ablation performed and the amount of sclerosantdelivered to the target treatment site. This not only creates aperception of a difficult-to-use device, but also may lead to inferioror incomplete venous ablation, e.g., if an insufficient amount ofsclerosant is delivered.

A related limitation of the prior art is that many current injectionmethods do not isolate the sclerosant within the vessel being treated.Some patients may be sensitive to sclerosant, and if this fluid migratesor embolizes into undesired locations, complications can result.Additionally, if the sclerosant is not contained or isolated, a lesservolume may end up penetrating into the vessel wall, leading to reducedtreatment efficacy.

FIG. 1 is a conceptual diagram of a vessel-ablation system 100, inaccordance with one or more techniques of this disclosure. Ablationsystem 100 includes a catheter 102 and in some examples, but not allexamples, an introducer sheath 104. Catheter 102 defines an elongatedbody 106 having a proximal portion 108 and a distal portion. Ablationsystem 100 further includes an ablation device 114 disposed at thedistal portion 110 of elongated body 106, and a manual control device112 (e.g., a handle) disposed at the proximal portion 108 of elongatedbody 106. In various examples herein, control device 112 and/or ablationdevice 114 may be integral components of catheter 102 (e.g., may berigidly coupled to elongated body 106), or alternatively, may beremovably coupled to catheter 102, as detailed further below withrespect to FIG. 3 .

As described above, control device 112, such as a proximal handle ofcatheter 102, includes one or more user controls configured to operatevarious aspects of ablation device 114. In particular, control device112 includes at least one user control configured to simultaneouslyactuate at least two clinical functions of ablation device 114. Forinstance, a single user control of control device 112 may be configuredto simultaneously actuate an agitator mechanism of ablation device 114and infuse a chemical agent (e.g., a sclerosant) from ablation device114. As another example, a single user control of control device 112 maybe configured to simultaneously infuse a chemical agent from ablationdevice 114 and longitudinally translate (e.g., proximally withdrawand/or distally advance) ablation device 114 relative to control device112. As another example, a single user control of control device 112 maybe configured to simultaneously longitudinally translate ablation device114 relative to control device 112 and actuate an agitator mechanism ofablation device 114. As another example, a single user control ofcontrol device 112 may be configured to simultaneously control all threeof: an actuation of an agitator mechanism of ablation device 114, alongitudinal translation of ablation device 114, and infusion of achemical agent from ablation device 114.

FIG. 2 is a conceptual diagram illustrating a non-limiting exampleapplication of ablation system 100 of FIG. 1 . In particular, FIG. 2illustrates ablation device 114 of FIG. 1 positioned within a targetvessel 202, such as a varicose vein. As shown in FIG. 2 , ablationdevice 114 includes a mechanical agitator 204, and means for infusing achemical agent 208, such as a sclerosant, into target vessel 202.Ablation system 100 further includes vessel occluder 216 configured toreduce or prevent fluid flow through target vessel 202.

In the scenario illustrated in FIG. 2 , a user (e.g., a clinician) ofablation system 100 has advanced ablation device 114 through introducersheath 104 and into target vessel 202, such as a varicose vein, within apatient's vasculature. Once ablation device 114 is positioned at targetvessel 202, the clinician may actuate user control 212, such as abutton, thumbwheel, switch, toggle, lever, dial, trigger, plunger, orthe like, integrated within control device 112. In accordance withtechniques of this disclosure, user control 212 is configured tosimultaneously govern at least two clinical functions of ablation system100. For instance, actuation of user control 212 may be configured toautomatically draw a predetermined volume (or predetermined flow rate)of a chemical agent 208 from a fluid reservoir 206, distally advancechemical agent 208 through an inner lumen 210 of elongated body 106, andrelease chemical agent 208 from ablation device 114 at the distalportion of elongated body 106 for infusion into target vessel 202.

Simultaneously, actuation of user control 212 may also be configured totrigger a preconfigured motion of mechanical agitator 204 of ablationdevice 114. In general, agitator 204 is configured to contact anddisrupt an interior surface of target vessel 202. In the particularexample of FIG. 2 , agitator 204 includes a pair of elongated tinesconfigured to mutually rotate about central longitudinal axis 214 ofelongated body 106. Additionally or alternatively, actuation of usercontrol 212 may be configured to simultaneously cause ablation device114, including agitator 204, to longitudinally translate, e.g.,proximally and/or distally parallel to central longitudinal axis 214, toengage agitator 204 across a greater portion of the interior wall oftarget vessel 202.

FIG. 3 is a conceptual diagram illustrating another example of ablationsystem 100 of FIG. 1 . As referenced above, FIG. 3 depicts an example inwhich a single-use (e.g., disposable) catheter 302 (e.g., catheter 102of FIG. 1 ) is removably coupled to a reusable control device 304 (e.g.,control device 112 of FIG. 1 ) via a connection interface 306. Suchimplementations provide for a number of benefits and practicalapplications. For instance, such implementations may be designed so asto reduce costs associated with both the manufacture and use of ablationsystem 100. As one example, reusable control device 304 may be operatedfrom a non-sterile environment 300A, thereby reducing costs associatedwith sterilizing equipment after completion of the procedure. Similarly,although catheter 302 is intended to function within a sterileintraoperative environment 300B, since catheter 302 and ablation device114 are designed to be postoperatively disposed, there is no obligationto postoperatively sterilize these components either.

In some example implementations of the system shown in FIG. 3 , controldevice 304 may be configured to be reusable via separation of thefluid-infusion pathway (e.g., lumen 210) from the internal components ofcontrol device 304, as detailed further below with respect to FIGS.4A-4C. Thus, control device 304 can be configured to be purchasedseparately from single-use catheter 302, which can decrease costs. Forinstance, because control device 304 (e.g., the handle) is reusable,additional design features that may otherwise have been cost-prohibitivecan instead become viable to produce. However, because the single-usecatheter 302 contacts at least a portion of the inside of control device304, control device 304 should define a form-factor small enough toautoclave (e.g., heat-sterilize), as appropriate.

FIG. 3 further illustrates some example components of control device304, any or all of which may be included within any of the examples ofcontrol device 112 described throughout this disclosure. As shown inFIG. 3 , control device 304 includes at least three user controls (e.g.,user control 212 of FIG. 2 ): an agitator input 308, a fluid-infusioninput 310, and a longitudinal-translation input 312. However, it is tobe understood that at least two of these three user controls may beoperatively coupled to, or integrated within, a common user-inputmechanism, such as a button, lever, knob, dial, switch, touchscreen,keypad, or the like.

As shown in FIG. 3 , agitator input 308 is operatively coupled to anagitator driver 316, such as a motor or other suitable mechanismconfigured to drive the preconfigured motion of agitator 204 (FIG. 2 ).Similarly, longitudinal-translation input 312 is operatively coupled toa longitudinal-translation driver 318, configured to drive alongitudinal motion of ablation device 114 through target vessel 202. Insome examples, but not all examples, agitator driver 316 andlongitudinal-translation driver 318 may be the same component, or mayshare common sub-components, as detailed further below.

In the example of FIG. 3 , control device 304 also includes a rate input314 (e.g., user control 212 of FIG. 2 ) enabling the clinician tocustomize two or more functional rates or amounts associated withablation device 114 relative to one another. For instance, rate input314 may enable the clinician to select a particular infusion-flow-rateof chemical agent 208 (FIG. 2 ), relative to alongitudinal-translation-rate of ablation device 114 through targetvessel 202, or relative to a preconfigured-motion (e.g., rotation,vibration, oscillation, etc.) rate of agitator 204. In this way, theclinician can more-conveniently and more-precisely control the operationof ablation system 100.

In one particular example, rate input 314 enables the clinician toselect milliliters of chemical agent 208 per millimeters of longitudinaltranslation. For instance, this feed rate could be modified viadifferent orifice sizes, e.g., using a Tuohy-Borst adaptor. Additionallyor alternatively, various gear-ratios may be implemented to modify theserates. Additionally or alternatively, two tubes of different diametersand/or orifice diameters may be used—i.e., a “storage” tube feeding intoan “active” tube.

FIGS. 4A-4C are cross-sectional views through three respective examplesof elongated body 106 of catheter 102 FIG. 1 . In the example shown inFIG. 4A, catheter 102 includes both an outer elongated body 106 defininginner lumen 210, and an elongated inner tubular member 408 positionedwithin inner lumen 210. In some such examples, inner elongated member408 can include a plurality of nested (e.g., coaxial) tubular layers: anouter tube 402, a middle tube 404, and an inner tube 406. That is, theelongated body 106 of the catheter 102 includes inner tube 406 disposedwithin an internal portion of the elongated body 106, middle tube 404that substantially surrounds the inner tube 406, and an outer tube 402that substantially surrounds the inner tube 406 and the middle tube 404.Any or all of tubes 402-406 may be formed from a polymer, such as athermoplastic elastomer.

In one illustrative, non-limiting example, inner tube 406 is formed frometched polytetrafluoroethylene (PTFE), and middle tube 404 and outertube 402 are formed from polyether block amide (e.g., Pebax™). Suchmaterials may allow the elongated body 106 of the catheter 102 and thetubes 402-406 to be more lubricious to facilitate movement along aguidewire (not shown) positioned within inner lumen 210. Additionally,the thermoplastic, PTFE, and/or polyether block amide may result inimproved flexibility and improved manufacturability of elongated body106, as these materials facilitate mutual bonding between the variousnested layers.

FIG. 4B illustrates an example of elongated body 106 defining twodistinct (e.g., fluidically insulated) inner lumens: a guidewire lumen410A and a fluid-infusion lumen 410B. Guidewire lumen 410A is configuredto receive a guidewire (not shown) to help advance catheter 102 throughthe patient's vasculature toward the target vessel. Fluid-infusion lumen410B is configured to distally transfer a chemical agent 208 (FIG. 2 ),such as a sclerosant, toward the target vessel 202. As referenced abovewith respect to FIG. 3 , fluid-insulation of chemical agent 208 fromother mechanical components of system 100 in this way (e.g., withdistinct lumens) can help enable certain functions and other advantages,such as reusability of control device 304.

FIG. 4C illustrates another example of elongated body 106 having a thirdlumen, such as a fluid-aspiration lumen 410C, that is fluidicallydistinct from lumens 410A and 410B. For instance, fluid-aspiration lumen410C may be configured to proximally transmit a fluid, such as a volumeof the patient's blood, or a volume of previously infused sclerosant,away from the target vessel for withdrawal from the patient'svasculature. It is understood that the cross-sectional shapes of thelumens as shown are merely exemplary, and that additional lumens may bepresent in the system, up to and including as many lumens as can fitwithin elongated body 106 while still maintaining the usability ofablation system 100.

FIG. 5 is a profile view of an example ablation device 514 (e.g.,ablation device 114 of FIG. 1 ) having a mechanical agitator 504 (e.g.,agitator 204 of FIG. 2 ). Agitator 504 includes a plurality of elongatedtines 506 distributed circumferentially around the distal portion 110 ofelongated body 106. More specifically, elongated tines 506 are rigidlycoupled to an outer surface of inner member 408. Inner member 408 andelongated tines are configured to extend longitudinally through innerlumen 210 of elongated body 106 and distally outward from distalcatheter mouth 510.

Agitator 504 represents a “straight tine” agitator, in which elongatedtines 506 extend generally parallel to central longitudinal axis 214. Insome examples, agitator 504 is configured to rotate about longitudinalaxis 214, causing tines 506 to disrupt or score the interior wall of thetarget vessel to improve absorption of chemical agent 208 (FIG. 2 ).Additionally or alternatively, agitator 504 may be configured to moveaccording to other predetermined motions, such as oscillatinglongitudinally along longitudinal axis 214, vibrating, or a combinationthereof. While agitator 504 is illustrated in FIG. 5 to include sixelongated tines 506, it is understood that agitator 504 may include anysuitable number of elongated tines 506. In the example shown in FIG. 5 ,a distal-most tip of each elongated tine is twisted relative to aninternal axis of the respective tine, providing for aneven-more-irregular surface for contacting and scoring the target vessel202. In other examples, tines 506 can include sharp points or hookedblades to penetrate deeper into or through the target vessel 202.

FIG. 6 is a profile view of ablation device 614 (e.g., ablation device114 of FIG. 1 ) having an example agitator 604 (e.g., agitator 204 ofFIG. 2 ) of ablation device 114 of FIG. 1 . Agitator 604 includes aplurality of elongated tines 606 distributed circumferentially around,and rigidly coupled to, an exterior surface of the distal portion 110(FIG. 1 ) of elongated body 106. Agitator 604 represents a “spiral tine”agitator, in which elongated tines 606 extend according to a spiral orhelical configuration, both distally along longitudinal axis 214, andalso circumferentially around longitudinal axis 214. Similar to agitator504 of FIG. 5 , agitator 604 of FIG. 6 may be configured to rotate,oscillate, vibrate, and/or move according to any suitable motion inorder to contact and disrupt the interior wall of the target vessel.

While five elongated tines 606 are illustrated in FIG. 6 , it isunderstood that agitator 604 may include any suitable number ofelongated tines 606. As shown in the close-up view inset in FIG. 6 , insome examples, but not all examples, a distal-most end of each elongatedtine 606 may terminate with a spherical tip 608 configured to increasean applied pressure against the vessel wall via contact with the reducedsurface area at any given point along the rounded surface of sphericaltip 608.

FIG. 7 is a profile view of an ablation device 714 (e.g., ablationdevice 114 of FIG. 1 ) having a plurality of fluid microtubes 706configured to extend distally outward from distal catheter mouth 510.Fluid microtubes 706 are primarily configured to deliver chemical agent208 (e.g., a sclerosant) into the target vessel 202 (FIG. 2 ). In someexamples, but not all examples, fluid microtubes 706 may additionally beconfigured to perform similar functionality to elongated tines 506, 606of FIGS. 5 and 6 , respectively. That is, fluid microtubes 706 may beconfigured to rotate, oscillate, vibrate, or otherwise move relative tocentral longitudinal axis 214 in order to contact and disrupt the innerwall of target vessel 202.

FIGS. 8A-8C are perspective views illustrating three non-limitingexamples of one of fluid microtubes 706 of FIG. 7 . For instance, FIG.8A illustrates a shape-memory microtube 806A. Shape-memory microtube806A may be formed from a shape-memory material (e.g., Nitinol), may bewrapped in a shape-memory-material coil 808, or both, such that fluidmicrotube 806A automatically conforms to a desired shape configurationfor infusion of chemical agent 208.

FIG. 8B illustrates a fluid microtube 806B defining a single fluidaperture 810 configured to release chemical agent 208. In the exampleshown in FIG. 8B, fluid aperture 810 is disposed just proximal tospherical tip 608, although this position is not intended to belimiting. Similar to the example shown in FIG. 6 , spherical distal tip608 may be configured to contact and disrupt the inner wall of targetvessel 202 (FIG. 2 ). By comparison, FIG. 8C illustrates a “porous”fluid microtube 806C defining a plurality of fluid apertures configuredto release chemical agent 208.

In the example shown in FIG. 8B, fluid aperture 810 is disposed justproximal to spherical tip 608, although this position is not intended tobe limiting. Similar to the example shown in FIG. 6 , spherical distaltip 608 may be configured to contact and disrupt the inner wall oftarget vessel 202 (FIG. 2 ).

FIGS. 9A-9D illustrate a technique for using an example ablation device914, which is an example of ablation device 114 of FIG. 1 . Ablationdevice 914 includes a self-expanding agitator 904 (e.g., agitator 204 ofFIG. 2 ) defining a plurality of elongated tines 906. As shown in FIGS.9A-9D, tines 906 may be distal extensions of a common band or ringadhered to the exterior surface of elongated body 106.

Prior to deployment, elongated tines 906 may be contained and compressedradially inward by a retainer element 902, which may be coupled to innermember 408 extending through inner lumen 210 of elongated body 106. Asshown in FIG. 9A, inner member 408 and retainer 902 may be advanceddistally (e.g., as indicated by the right-facing arrow) relative toagitator 904, releasing agitator 904 from inside retainer 902 andenabling tines 906 to deform radially outward into their predetermineddeployed configurations.

In some examples, such as the example shown in FIG. 9B, inner member 408can take the form of a porous elongated inner member. In such examples,the clinician can actuate one of user controls 212 (FIG. 2 ) to releaseand infuse chemical agent 208 from inner member 408. Additionally oralternatively, as shown in FIGS. 9C and 9D, ablation device 114 caninclude a porous or “weeping” interventional balloon 910. In suchexamples, the clinician can actuate one of user controls 212 to at leastpartially inflate balloon 910 with chemical agent 208 (FIG. 9C), wherethe chemical agent 208 can then infuse outward through the surface ofballoon 910 (FIG. 9D).

FIG. 10 is a profile view of another example ablation device 1014 (e.g.,ablation device 114 of FIG. 1 ) having a self-expanding agitator 1004(e.g., agitator 904 of FIGS. 9A-9D) having a plurality of elongatedtines 1006. Unlike tines 906 of FIGS. 9A-9D, which are coupled to anexterior surface of elongated body 106, tines 1006 of FIG. 10 arecoupled to inner member 408 positioned within inner lumen 210. Duringuse, the clinician may actuate one of use controls 212 (FIG. 2 ) toadvance inner member 408 distally through inner lumen 210 until tines1006 self-expand radially outward through respective apertures 1012defined by elongated body 106.

FIG. 11 illustrates a gear-and-track mechanism 1100 for ablation system100 of FIG. 1 . Gear-and-track mechanism 1100 may be an example oftranslation driver 318 of FIG. 3 . That is, the gear-and-track mechanism1100 is configured to at least move ablation device 114 (FIG. 1 )longitudinally (e.g., proximally and/or distally) relative to controldevice 112 in response to user-actuation of translation input 312 (FIG.3 ). For instance, although not shown in FIG. 11 , linear-translationinput 312 of FIG. 3 , such as a thumbwheel or the like, may beoperatively coupled to wheel gear 1102, which, in turn, is operativelycoupled to first track 1104A and second track 1104B. First track 1104Aand second track 1104B may be positioned on opposite sides (e.g., topand bottom, from the perspective shown in FIG. 11 ) of wheel gear 1102,such that, when wheel gear 1102 rotates (e.g., in response to actuationof translation input 312), first track 1104A and second track 1104B movelongitudinally in opposing directions. In response, ablation device 114(FIG. 1 ), which is rigidly coupled to either first track 1104A orsecond track 1104B, moves longitudinally parallel to centrallongitudinal axis 214.

FIGS. 12A and 12B illustrate a worm-gear mechanism 1200, in which awheel gear 1208, which may be a thumbwheel, or may be rigidly coupled toa thumbwheel (e.g., user control 212 of FIG. 2 ) is operatively engagedwith a worm gear 1202. Worm gear 1202 includes a longitudinal shaft1204, and a coiled thread 1206 extending both longitudinally along andcircumferentially around longitudinal shaft 1204. Longitudinal shaft1204 is an example of inner elongated member 408 of FIG. 4 , e.g., isconfigured to fit within inner lumen 210 of elongated body 106.

As shown in FIG. 12A, ablation device 114 may be rigidly coupled to adistal portion of longitudinal shaft 1204, such that rotation of wheelgear 1208 (e.g., in response to user-actuation of translation input 312of FIG. 3 ), ablation device 114 moves proximally and/or distally alonglongitudinal axis 214.

In some examples, the configuration of wheel gear 1208 relative to wormgear 1202 can enable worm gear 1202 to simultaneously translate alonglongitudinal axis 214 and rotate about longitudinal axis 214.Accordingly, for examples in which ablation device 114 includes arotational agitator 204 (e.g., FIG. 2 ), a single user control 212 (FIG.2 ) can be configured to actuate both longitudinal translation androtation of agitator 204. In fact, worm gear 1202 can be configured tosimultaneously enable any, or even all three of, the ablative functionsdescribed above, including longitudinal translation of agitator 204,rotation of agitator 204, and infusion of chemical agent 208. Forinstance, as illustrated in FIG. 12B, coiled thread 1206 can befluidically sealed against an interior surface of the inner lumen 210such that worm gear 1202 functions as an Archimedes screw, configured topump chemical agent 208 distally along longitudinal axis 214 aslongitudinal shaft 1204 rotates about longitudinal axis 214. Accordingto similar principles, the rotational direction of worm gear 1202 may beinverted so as to proximally aspirate a fluid, such as previouslyinfused sclerosant, or a volume of the patient's blood, away from targetvessel 202.

According to the configuration shown in FIG. 12B, a fluid volume ofchemical agent 208 delivered to the target vessel is directly correlatedwith the number of rotations of the mechanical agitator 204 (FIG. 2 ),eliminating the need for the clinician to consciously calibrate andmanually maintain the relative rates between these two variables duringthe ablation treatment. In some examples, the fluid volume (or flowrate) of chemical agent 208 delivered to the target vessel can beincreased by increasing the “head pressure” of chemical agent 208, e.g.,near the proximal portion 108 of catheter 102 (FIG. 1 ). The cliniciancan adjust this head pressure, for example, by adjusting the height offluid reservoir 206 (FIG. 2 ), e.g., a sclerosant-solution bag, abovethe patient. For instance, the clinician may adjust the height of fluidreservoir 206 by a distance proportional to the inner diameter (orcross-sectional area) of target vessel 202, thereby customizing thetotal delivered fluid volume (or fluid flow-rate, as appropriate) tomore-effectively treat the target vessel. Such adjustments may beperformed automatically, e.g., by a machine configured to preciselyadjust reservoir height based on vessel-diameter sensor data oruser-input values, or alternatively, may be performed manually by theclinician's team upon consulting a lookup table (or the equivalent)indicating predetermined relationship(s) between fluid-reservoir heightand vessel diameter.

According to the techniques of this disclosure, additional oralternative forms of autoregulation may be present for fluid infusion.For instance, mechanical elements of ablation device 114 (e.g., agitator204) may be expanded to accommodate a larger-diameter target vessel 202,which may require a commensurate radial expansion of distal cathetermouth 510. As distal catheter mouth 510 expands, the fluid-resistanceagainst a flow of chemical agent 208 decreases, thereby increasing thevolume of chemical agent 208 delivered to the target vessel (assumingconstant head pressure). In this way, ablation system 100 may beconfigured to automatically “calibrate” the volume (or flow rate) ofinfused chemical agent 208, and the “amount” of mechanical agitation(e.g., number and/or rate of agitator rotations), as a function ofvessel size, i.e., providing more sclerosant and agitation tolarger-diameter vessels, and less sclerosant and agitation tosmaller-diameter vessels. In some such examples, the need for ultrasonicimaging (or the equivalent) to indicate the relative position ofablation device 114 and/or the delivered volume of chemical agent 208may be significantly reduced, or even eliminated.

As another example of the autoregulation of ablation system 100, variousexamples described herein include porous weeping balloons (e.g., balloon910 of FIGS. 9C and 9D). The weeping balloons can be designed to be“oversized” such that they remain wrapped, folded, or pleated withinsmaller-diameter vessels. These folds and pleats will mutually seal manyof the fluid micropores against each other, thereby reducing the amountand/or rate of chemical agent 208 weeping through the balloon. Forlarger-diameters vessels, the balloon may expand further, exposing moreof the micropores and allowing a larger amount of chemical agent 208 toweep through thereby more-effectively treating target vessel 202.

The examples shown in FIGS. 11-12B are intended to illustrate high-levelconcepts, and are not intended to be limiting. For instance, otherexamples may include additional gears configured to provide spacebetween adjacent components and/or to enable control over the resultinggear ratios, such that the linear translation, fluid infusion, andmechanical agitation can be precisely customized by the user toaccommodate the unique clinical parameters presented.

FIGS. 13A-13C depict an example dual-worm-gear mechanism 1300 for theablation system of FIG. 1 . Dual-worm-gear mechanism 1300 is an exampleof worm-gear mechanism 1200 of FIGS. 12A and 12B, except for thedifferences noted herein. For instance, dual-worm-gear mechanism 1300may be used to infuse chemical agent 208 using similar principles (e.g.,Archimedes screw pumps) as described above with respect to FIG. 12B.

As shown in FIGS. 13A-13C, dual-coaxial-worm-gear mechanism 1300includes a thumbwheel 1308 (e.g., user control 212 of FIG. 2 , andfluid-infusion input 310 and translation input 312 of FIG. 3 )operatively engaged with a dual coaxial worm gear 1302. Dual coaxialworm gear 1302 includes an outer longitudinal shaft 1304A; an outercoiled thread 1306A extending both longitudinally along andcircumferentially around outer longitudinal shaft 1304A; an innerlongitudinal shaft 1304B disposed within an inner lumen of outerlongitudinal shaft 1304A; and an inner coiled thread 1306B extendingboth longitudinally along and circumferentially around innerlongitudinal shaft 1304B. Longitudinal shafts 1304A, 1304B are bothexamples of inner elongated member 408 of FIG. 4 , e.g., are configuredto fit within inner lumen 210 of elongated body 106.

In a first example, a mechanical interaction between rotating thumbwheel1308 and outer coiled thread 1306A drives a longitudinal (e.g., distal)motion of a syringe plunger (not shown), thereby infusing chemical agent208 into the target vessel. Simultaneously, the mechanical interactionbetween rotating thumbwheel 1308 and inner coiled thread 1306B drives alongitudinal (e.g., proximal) motion of ablation device 114, therebylongitudinally translating mechanical agitator 204 across the inner wallof target vessel 202.

In a second example, a mechanical interaction between rotatingthumbwheel 1308 and outer coiled thread 1306A drives a longitudinal(e.g., proximal) motion of ablation device 114, thereby linearlytranslating mechanical agitator 204 across the inner wall of the targetvessel. Simultaneously, the mechanical interaction between rotatingthumbwheel 1308 and inner coiled thread 1306B drives a longitudinal(e.g., distal) motion of a syringe plunger (not shown), thereby infusingchemical agent 208 into the target vessel.

In either example, the relative speeds of the two longitudinal motionsare determined by the pitch ratio between outer coiled thread 1306A andinner coiled thread 1306B. For instance, in the example illustrated inFIGS. 13A-13C, outer coiled thread 1306A has a much “tighter”configuration than inner coiled thread 1306B, in that adjacent turns ofouter coiled threads 1306A are significantly closer together thanadjacent turns of inner coiled threads 1306B. Accordingly, when outerlongitudinal shaft 1304A and inner longitudinal shaft 1304Bsimultaneously rotate about longitudinal axis 214, inner longitudinalshaft 1304B (and any components rigidly coupled to it) travels asignificantly longer distance along longitudinal axis 214 than outershaft 1304A does.

Additionally or alternatively, dual-worm-gear mechanism 1300 may beconfigured to provide a rotational motion of ablation device 114,thereby enabling precise user control over all three functions oflongitudinal translation, agitator rotation, and fluid infusion via asingle user-input mechanism, i.e., thumbwheel 1308.

FIG. 14 is a transparent perspective view of a manual control device1412 (e.g., proximal control device 112 of FIG. 1 ) having an integratedspur-gear mechanism 1402. As used herein, a “spur gear” refers to agearwheel with teeth defining both a radial length extending radiallyoutward from the gear's rotational axis, and an axial length extendingparallel to the gear's rotational axis.

In the example of FIG. 14 , control device 1412 includes a thumbwheel1404 (e.g., user control 212 of FIG. 2 , fluid-infusion input 310, andtranslation input of 312 of FIG. 3 ) enabling the clinician tosimultaneously infuse chemical agent 208 and longitudinally translateablation device 114 (e.g., agitator 204). Thumbwheel 1404 isuser-rotatable about a wheel axis 1406 perpendicular to centrallongitudinal axis 214, and is operatively engaged with both syringeplunger 1410 and wheel gear 1408.

From the perspective of FIG. 14 , a clockwise rotation of thumbwheel1404 drives syringe plunger 1410 to the left, thereby infusing chemicalagent 208 into the inner lumen 210 (FIG. 2 ) of elongated body 106.

Additionally, elongated body 106 is friction-pinched between a pair ofcatheter rollers 1414 engaged with wheel gear 1408, such that the sameclockwise rotation of thumbwheel 1404 drives elongated body 106 to theleft, thereby retracting ablation device 114 proximally through targetvessel 202 (FIG. 2 ).

In other examples, control device 1412 can include any suitable numberof interlocking gears, enabling the user to modify (e.g., customize) therelative relationships between rotational motion of thumbwheel 1404,longitudinal motion (e.g., proximal retraction) of ablation device 114,and/or longitudinal motion (e.g., distal advancement) of syringe plunger1410 (e.g., fluid-infusion flowrate) to accommodate the unique clinicalneeds presented.

FIG. 15 is a transparent perspective view of a manual control device1512 (e.g., proximal control device 112 of FIG. 1 ) having an integratedrear-spur-gear mechanism 1502. Rear-spur-gear mechanism 1502 is anexample of spur-gear mechanism 1402 of FIG. 14 , except for thedifferences noted herein.

For instance, unlike spur-gear mechanism 1402, in which thumbwheel 1404is directly engaged with syringe plunger 1410, in rear-spur-gearmechanism 1502 of FIG. 15 , thumbwheel 1404 is indirectly engaged withsyringe teeth 1508 via wheel gear 1408, such that, from the perspectiveof FIG. 15 , a counterclockwise (rather than clockwise) rotation ofthumbwheel 1404 drives syringe plunger 1410 to the left, therebyinfusing chemical agent 208 into the inner lumen 210 of elongatedcatheter body.

Similarly, unlike spur-gear mechanism 1402 in which thumbwheel 1404 isindirectly engaged with catheter rollers 1414 via wheel gear 1408, inrear-spur-gear mechanism 1502 of FIG. 15 , thumbwheel 1404 is directlyengaged with catheter rollers 1414, such that, from the perspective ofFIG. 15 , the same counterclockwise (rather than clockwise) rotation ofthumbwheel 1404 drives elongated body 106 to the left, therebyproximally retracting ablation device 114 through the target vessel. Putsimply, in FIG. 15 , the direction of rotation of thumbwheel 1404 isaligned with the operational motions of syringe plunger 1410 andelongated body 106, whereas in FIG. 14 , the direction of rotation ofthumbwheel 1404 is anti-aligned with the operational motions of syringeplunger 1410 and elongated body 106.

Also shown in FIG. 15 is an optional trigger lock 1510 coupled tocatheter rollers 1414, enabling the clinician to lock elongated body 106in place, and subsequently release, as appropriate. In other examples,control device 1512 can include any suitable number of interlockinggears, enabling the user to modify (e.g., customize) the relativerelationships between rotational motion of thumbwheel 1404, longitudinalmotion (e.g., proximal retraction) of ablation device 114, and/orlongitudinal motion (e.g., distal advancement) of syringe plunger 1410(e.g., fluid-infusion flowrate) to accommodate the unique clinical needspresented.

FIG. 16 is a profile view of an example control device 1614 having a“forward” pulley mechanism 1600 configured to drive a longitudinal(e.g., proximal or distal) translation of ablation device 114. Forinstance, through standard principles, pulley mechanism 1600 isconfigured to convert a rotational motion, such as from a motor 1602(e.g., translation driver 318 of FIG. 3 ) or from manual user-actuationof wheel 1604 (e.g., translation input 312), into a longitudinal motionalong central axis 214, thereby proximally withdrawing ablation device114 through the target vessel 202 within the patient's vasculature. Insome examples, pulley mechanism 1600 simultaneously drives infusion ofchemical agent 208 into target vessel 202, according to principlessimilar to those described above, without requiring additional manualuser input and/or internal mechanical functionality.

FIG. 17A is a profile view, and FIG. 17B is a conceptual diagram,illustrating a manual control device 1712 (e.g., proximal control device112 of FIG. 1 ) having an example “reverse” pulley mechanism 1700.Similar to control devices 1412 and 1512 of FIGS. 14 and 15 ,respectively, in response to actuation of a user control (in this case,via depression of syringe plunger 1410), control device 1712 isconfigured to simultaneously drive both longitudinal translation ofelongated body 106 and infusion of chemical agent 208. Also similar tocontrol devices 1412 and 1512 is that elongated body 106 extendsproximally from the proximal side of housing 1706 of control device1712, and then loops back and feeds distally through an aperture 1704defined by housing 1706.

As shown in FIG. 17B, reverse pulley mechanism 1700 includes a pluralityof pulley wheels 1708 configured to decrease an applied force necessaryfor longitudinal translation of elongated body 106 and/or syringeplunger 1410. Reverse pulley mechanism 1700 further includes one or moreadjustable knobs 1710 configured to enable the user to customize therate of motion of syringe plunger 1410 (i.e., the rate of fluidinfusion) relative to the rate of motion of elongated body 106 (i.e.,the proximal retraction of agitator 204).

FIGS. 18A-18C illustrate an example straight-syringe catheter 1802(e.g., catheter 102 of FIG. 1 ) in a proximally retracted configuration,and FIGS. 19A-19C illustrate straight-syringe catheter 1802 in adistally advanced configuration. More specifically, FIG. 18A is aprofile view of straight-syringe catheter 1802, and FIG. 18B is aprofile view of a proximal portion 1808 (e.g., proximal portion 108 ofFIG. 1 ) of straight-syringe catheter 1802. As shown in FIGS. 18A and18B, straight-syringe catheter 1802 includes an elongated body 1806(e.g., elongated body 106 of FIG. 1 ), a control knob 1812 (e.g.,control device 112 of FIG. 1 ) and a grip 1818 at the proximal portion1808 of elongated body 1806, and an ablation device 114 at a distalportion 1810 (e.g., distal portion 110 of FIG. 1 ) of elongated body1806. In FIGS. 18A and 18B (but not FIG. 18C), control knob 1812 ispositioned slightly proximal from grip 1818, with a longitudinal gaptherebetween.

Control knob 1812, which may be a plunger of a syringe, is free torotate about longitudinal axis 214 (FIG. 18C), relative to indicatorhandle 1820. Such rotational motion may be manual (e.g., user-driven),or automatic. In some examples, this rotational motion may be translatedthrough elongated body 1806 (or other elongated member 408 therein) andimparted into a rotational agitator 204 (or other similarvessel-abrading mechanism) of ablation device 114.

As shown in FIGS. 18A-19C, elongated body 1806 of straight-syringecatheter 102 extends through a displacement indicator 1816 having anindicator handle 1820. Displacement indicator 1816 includes a pluralityof longitudinally spaced demarcations enabling the clinician to estimatea length of elongated body 1806 positioned within the patient'svasculature based on how far toward the indicator handle 1820 thatcontrol knob 1812 has moved, thereby allowing for precise control overcatheter advancement and withdrawal, and even over rates of speedthereof. In some examples, displacement indicator 1816 additionallyenables the clinician to estimate a volume of chemical agent 208 infusedinto the target vessel (and even a rate of speed thereof).

In the examples shown in FIGS. 18A-18C, control knob 1812 and grip 1818are positioned significantly proximally from displacement indicator1816, indicating that the straight-syringe catheter 1802 is in aproximally retracted configuration. By contrast, in the examples shownin FIGS. 19A-19C, control knob 1812 and grip 1818 are significantlycloser to displacement indicator 1816, indicating that thestraight-syringe catheter 1802 is now in a distally advancedconfiguration. In other words, control knob 1812 and grip 1818 have beenadvanced distally toward displacement indicator 1816, thus advancingelongated body 1806 distally through displacement indicator 1816 andoutward from a distal mouth 1822 of displacement indicator 1816,permitting insertion into the vasculature of the patient. As controlknob 1812 advances distally toward displacement indicator 1816, theguidewire tube (not shown), and elongated body 1806 translate distallyas well. There is a direct relationship between the longitudinaldisplacement of control knob 1812 relative to displacement indicator1816, and the longitudinal displacement of the guidewire tube andelongated body 1806 within the patient's vasculature. This relationshipmay be a direct (e.g., one-to-one) correlation, or may beuser-customizable.

FIG. 20 is a profile view of an example control device 2012 (e.g.,control device 112 of FIG. 1 ) having a user control (e.g., user control212 of FIG. 2 , translation input 312 of FIG. 3 ) in the form of asliding mechanism. During use, the clinician can distally advance slider2002 from retracted position 2002A to advanced position 2002B in orderto extend elongated body 106 distally outward from distal mouth 2022.Once ablation device 114 is positioned within the target vessel, theclinician can then proximally retract slider 2002 from advanced position2002B to retracted position 2002A in order to linearly translateagitator 204 (FIG. 2 ) across the inner wall of the target vessel 202.

As illustrated in FIG. 20 , an exterior surface of control device 2012includes a plurality of demarcations forming a displacement indicator2016, enabling the clinician to determine the distance the catheter hasbeen extended based on how far along the handle the control has moved,thus allowing for fine-tuned control of how far the user is inserting orretracting the catheter, as well as the speed at which they are doingso.

In some examples, control device 2012 includes a fluid reservoir 206(FIG. 2 ), e.g., contained within external housing 2006. Fluid reservoir206 stores chemical agent 208, such as a sclerosant, for injectionthrough inner lumen 210 of elongated body 106 and infusion into thetarget vessel 202. In some such examples, displacement indicator 2016enables the clinician to visualize a volume and/or a rate offluid-infusion from reservoir 206.

FIGS. 21A and 21B are profile views of an example manual control device2112 (e.g., proximal control device 112 of FIG. 1 ) having a usercontrol 2102 (e.g., user control 212 of FIG. 2 ) in the form of atwo-finger pullback mechanism. User control 2102 is configured to enablethe clinician to distally infuse chemical agent 208, proximallytranslate ablation device 114, or both. Additionally or alternatively,since user control 2102 is free to rotate about longitudinal axis 214relative to elongated body 106 (e.g., via user actuation of thumbwheel2104), this rotation may be imparted through inner lumen 210 ofelongated body 106 and into agitator 204 (FIG. 2 ). As shown in FIGS.21A and 21B, demarcations may be present along a portion of controldevice 2112, forming a displacement indicator 2016, as described above.

FIG. 22 is a conceptual diagram of an example ablation device 2214(e.g., ablation device 114 of FIG. 1 ) of ablation system 100. Ablationdevice 2214 is an example of an Isolated, Segmental Mechanical-chemicalAblation (ISMA) device. In the example shown in FIG. 22 , ISMA deviceincludes proximal and distal balloons 2202A, 2202B (e.g., vesseloccluder 216 of FIG. 2 ) spaced longitudinally apart along centrallongitudinal axis 214. Proximal balloon 2202A is located closer tocontrol device 112 (FIG. 1 ), and distal balloon 2202B is located nearor at the distal end of elongated body 106. A length of elongated body106 positioned within the longitudinal gap between proximal and distalballoons 2202 can define a plurality of fluid apertures 810 for infusionof chemical agent 208. When balloons 2202 are inflated (or otherwiseexpanded), they are configured to occlude the target vessel, thereby“isolating” chemical agent 208 to be retained within the space betweenballoons 2202.

Ablation device 2214 further includes a manually operated orbattery-powered agitator 2206 (e.g., agitator 204 of FIG. 2 ) betweenballoons 2202. Agitator 2206 includes a polymer or metal wire configuredto move (e.g., rotate, oscillated, vibrate, etc.) to contact and scorethe target vessel wall to promote uptake of chemical agent 208. In someexamples, elongated body 106 defines a fluid-aspiration lumen 410C (FIG.4 ) enabling the clinician to proximally suction back any unused and/orunabsorbed chemical agent 208.

A general procedure for using the ablation system shown in FIG. 22starts near the junction of the great saphenous vein (GSV). Theclinician inflates proximal and distal balloons 2202, and aspirates anyblood from the resulting isolated vessel segment, placing the segmentunder negative pressure. The clinician infuses a predetermined amount ofchemical agent 208 into the isolated vessel segment, and actuatesagitator 2206 for a specified duration (e.g., 60 seconds). The clinicianthen aspirates any unused chemical agent 208 within the isolated segmentvia an intraluminal catheter. The clinician then deflates only proximalballoon 2202A while maintaining inflation of distal balloon 2202B,before proximally retracting catheter 102 in order to treat the nextisolated segment of the target vessel. Proximal balloon 2202A is thenreinflated, and the subsequent steps may be repeated as necessary tofully ablate the varicose vein.

FIG. 23 is a conceptual diagram of a manual control device 2312 (e.g.,proximal control device 112 of FIG. 1 ) having a continuous feed tube2302 configured to simultaneously infuse chemical agent 208 (FIG. 2 )and longitudinally translate ablation device 114, as described above.Continuous feed tube 2302 is driven by a piston 2304, which in turn isdriven by a flexible member. As used herein, a “flexible member” refersto any suitable non-rigid structure that may be used for longitudinallypushing or pulling elongated body 106, such as a cord, chain, rope,belt, or the like. When user control 2306 (e.g., user control 212) onthe bottom portion 2310 of continuous feed tube 2302 is pulled back, theflexible-member-driven piston 2304 pulls back on the bottom portion 2310and pulls forward on the top portion 2308. This pull-back on the bottomportion 2310 of the continuous feed tube 2302 is configured toproximally withdraw elongated body 106 from the target vessel 202 (FIG.2 ) within the patient's vasculature. Simultaneously, the pull-forwardon the top portion 2308 of the continuous feed tube 2302 is configuredto infuse chemical agent 208 from ablation device 114 at the distalportion of 110 catheter 102.

FIG. 24 is a conceptual diagram of a manual control device 2412 (e.g.,proximal control device 112 of FIG. 1 ) having a coiled feed tube 2402configured to simultaneously infuse chemical agent 208 (FIG. 2 ) andlongitudinally translate ablation device 114, as described above. Theclinician can manually actuate (e.g., twist) user control 2404 (e.g.,user control 212 of FIG. 2 , and fluid-infusion input 310 andtranslation input 312 of FIG. 3 ) to wrap or unwrap an elongated portionof coiled feed tube 2402 from around user control 2404. For instance, bytwisting user control 2404 clockwise (from the perspective shown in FIG.24 ), coiled feed tube 2402 becomes further wrapped around user control2404, thereby longitudinally translating (e.g., proximally withdrawing)ablation device 114 through target vessel 202. Simultaneously, theinternal compression imparted by the various turns of coiled feed tube2402 against one another causes chemical agent 208 retained withincoiled feed tube 2402 to be “squeezed” distally through elongated body106 and infused into the target vessel via ablation device 114.

In some examples, the coiled shape of feed tube 2402 enables thelongitudinal length of control device 2412 to be reduced, thusdecreasing the overall longitudinal footprint of ablation system 100. Itis to be understood that any feature, function, or element described inprevious or subsequent examples may also be incorporated into the otherexamples. For instance, consistent with other examples previouslydescribed, the ratio between the longitudinal displacement of elongatedbody 106 and the fluid volume (or flow rate) of chemical agent 208 canbe maintained or user-customized, as appropriate.

FIGS. 25A-25C are conceptual diagrams of ablation device 2514 (e.g.,ablation device 114 of FIG. 1 ) having radially expanding wings2502A-2502C, respectively, configured to agitate (e.g., vibrate orrotate) the target vessel and/or infuse chemical agent 208. Forinstance, FIGS. 25A and 25B illustrate a possible embodiment of thedistal portion of elongated body 106 in which the user may distallyadvance a proximal portion of elongated body 106, proximally retract adistal portion of elongated body 106 (e.g., via a pullwire), or both, tocause the catheter body to “split” into multiple segments distributedcircumferentially around inner member 408 before meeting again prior tothe distal tip, thereby forming a set of “winged” shapes 2502A, 2502B.

This “winged” shape 2502 enables ablation device 2514 catheter to makegreater contact with the inner wall of the target vessel 202, therebyimproving vessel abrasion. In the example of FIG. 25A, wings 2502A eachdefine an inner fluid-infusion lumen configured to infuse chemical agent208 directly into the target tissue. Additionally or alternatively, asshown in FIG. 25B, inner member 408 can define fluid apertures 810 (FIG.8 ) configured to infuse chemical agent 208 from between wings 2502B,enabling broader dispersion of the sclerosant.

Wings 2502C of FIG. 25C are examples of wings 2502A, 2502B, except that,instead of the radially expandable wings being formed from portions ofelongated body 106, ablation device 2514 includes one or more elongatedwires 2504 coupled to the exterior surface of elongated body 106,wherein the wires 2504 are configured to expand radially outward to formwings 2502C. Because the wire(s) 2504 can be made of a stronger, orsharper, material than elongated body 106, wire wings 2502C can furtherimprove abrasion of the target vessel.

FIGS. 26A-26C are conceptual diagrams of ablation device 2614 (e.g.,ablation device 114 of FIG. 1 ) having rotating diffusion brushes2602A-2602C (e.g., agitator 204 of FIG. 2 ) configured to agitate thetarget vessel 202 and/or infuse chemical agent 208. For instance, asshown in FIGS. 26A-26C, brushes 2602 are configured to extend distallyoutward from distal catheter mouth 510. In the example shown in FIG.26A, inner lumen 210 (e.g., fluid-infusion lumen 410B) provides chemicalagent 208 to target vessel 202, and may “wet” the brush 2602A withsclerosant while the brush 2602A is sheathed within inner lumen 210. Thebrush 2602A then rotates about longitudinal axis 214 to dispersechemical agent 208 across the target-vessel wall. In some examples,brush 2602A may have a user-variable longitudinal length, radialdiameter, and/or bristle stiffness configured to accommodate the uniqueclinical needs presented.

Additionally or alternatively, in the example shown in FIG. 26B, innermember 408 defines a plurality of fluid apertures 810 configured toinfuse chemical agent 208 along the bristles of brush 2602B. Chemicalagent 208 then “wicks” along the bristles and across the target-vesselwall.

Additionally or alternatively, in the example shown in FIG. 26C, eachbristle of brush 2602C defines a fluid microtube (e.g., fluid microtubes706, 806 of FIGS. 7-8C). For example, chemical agent 208 advancesdistally through inner member 408 of brush 2602C, and is then dispersedfrom aperture 810 at the radially-outermost end of each fluid-microtubebristle and across the target-vessel wall.

FIGS. 27A and 27B are conceptual diagrams of ablation device 2714 (e.g.,ablation device 114 of FIG. 1 ) having rotating hypotubes 2702A, 2702B,respectively. Hypotubes 2702 are examples of rotating agitator 204 ofFIG. 2 , and can be configured to rotate about longitudinal axis 214,either in response to manual user-actuation of a user control 212 (FIG.2 ), or to rotate automatically during longitudinal translation ofablation device 2714 through the target vessel. In some cases, hypotubes2702 can rotate fully circumferentially (e.g., a complete 360-degreesabout longitudinal axis 214), while in other examples, hypotubes 2702are configured to rotationally oscillate, e.g., rotate about only aportion of the circumference and then reverse the rotational direction.

As shown in FIG. 27A, hypotube 2702A defines a plurality of fluidapertures 810 configured to infuse chemical agent 208 into the targetvessel while hypotube 2702A is stationary, while hypotube 2702A isrotating, or both. Hypotube 2702A of FIG. 27A is illustrated as alaser-drilled hypotube having a distal portion oriented at an angle θrelative to central longitudinal axis 214. This angle can be selected tobe any suitable angle from zero degrees (e.g., parallel to longitudinalaxis 214) to ninety degrees (e.g., perpendicular to longitudinal axis214), however, an angle greater than zero enables the distal portion ofhypotube 2702A to contact and abrade the vessel wall. In some examples,the distal-most tip of hypotube 2702A may be either closed (e.g., forincreased vessel contact and abrasion), or open (e.g., for infusion ofchemical agent 208).

As shown in FIG. 27B, the distal portion of hypotube 2702B angles awayfrom longitudinal axis 214, then angles back to be parallel withlongitudinal axis 214, such that the distal portion of hypotube 2702B isradially offset from the central longitudinal axis 214, therebyproviding vessel-wall contact along the entire distal portion (ascompared to just at the distal-most tip, as with hypotube 2702A). Eitheror both of the offset angle θ and the offset distance may be adjusted bythe operator based on the presented clinical needs. In the example shownin FIG. 27B, a radial-outward-facing surface of the distal portion ofhypotube 2702B includes an abrading member 2704 (e.g., a rough orserrated surface) configured to further improve vessel-wall abrasionduring infusion of chemical agent 208.

FIGS. 28A and 28B are conceptual diagrams of an ablation device 2814(e.g., ablation device 114 of FIG. 1 ) having a sinusoidal agitator 2804(e.g., agitator 204 of FIG. 2 ). In either example, sinusoidal agitator2804 rotates either manually or automatically (e.g., under batterypower) about longitudinal axis 214, in order to contact and abrade thetarget-vessel wall.

In the example shown in FIG. 28A, agitator 2804 can be configured torotate about longitudinal axis 214, oscillate along longitudinal axis214, vibrate, or a combination thereof, in order to contact and abradethe target-vessel wall. The sinusoidal shape of agitator 2804 permitsmultiple points of contact, e.g., forming circumferential and/orhelical-shaped abrasions as agitator 2804 rotates (or otherwise moves)along the vessel wall. The elongated body of agitator 2804 defines aplurality of fluid apertures 810 configured to infuse chemical agent 208into the target vessel.

In the example shown in FIG. 28B, sinusoidal agitator 2804 is enclosedwithin an interventional balloon 910, such as weeping balloon 910 ofFIGS. 9C and 9D. In some such examples, in addition to contacting andabrading the vessel wall through the balloon membrane, agitator 2804 canalso function as a peristaltic pump by squeezing chemical agent 208through the porous balloon membrane as it rotates about longitudinalaxis 214.

FIGS. 29A and 29B are conceptual diagrams of an ablation device 2914(e.g., ablation device 114 of FIG. 1 ) having a rotating agitator 2904A,2904B (e.g., agitator 204 of FIG. 2 ) in the form of a wire-loopmechanism configured to contact and abrade the target-vessel wall.Agitator 2904A of FIG. 29A is a radially “narrower” wire loop having adistal end that forms a dull or rounded point 2902 configured to disruptthe vessel wall. By comparison, agitator 2904B of FIG. 29B is a radiallywider, more-circular wire loop providing a wider surface area forcontact with the vessel wall. Similar to other examples described above,agitators 2904A, 2904B can include fluid apertures 810 configured toinfuse chemical agent 208 into the target vessel. Additionally oralternatively, chemical agent 208 may be infused via distal cathetermouth 510.

FIG. 30 is a conceptual diagram of an example control device 3012 (e.g.,proximal control device 112 of FIG. 1 ) having a rotary syringe holder3002. Syringe holder 3002 is a quick-change system enabling the use ofmultiple syringes 3004, e.g., in order to either break up a singlechemical agent into a set of smaller, controlled infusion “doses,” oralternatively, in order to infuse a plurality of different chemicalagents at different times throughout the procedure. In some instances,the use of multiple, smaller-volume syringes 3004 can help reduce therisk of bolus injection.

In some examples, a proximal portion 108 (FIG. 1 ) of elongated body 106couples to a Y-hub 3006 with a slip-fit syringe connection. During use,rotary syringe holder 3002 rotates to fluidically couple a particularsyringe 3004 to the Y-hub connection. Syringe holder 3002 can translatelongitudinally to engage and disengage the syringe with the Y-hub 3006.In some examples, each syringe 3004 may have an individual slidingmechanism to deploy the plunger and inject the fluid into the catheter102. Additionally or alternatively, a single plunger 3008 at the backend may align with the syringe 3004 that is currently engaged with theY-hub 3006 to inject the fluid into the catheter 102, enabling allsyringes to be controlled by a single plunger 3008, thereby decreasingcosts of manufacture.

FIGS. 31A-31C are conceptual diagrams of ablation device 3114 (e.g.,ablation device 114 of FIG. 1 ) having a weeping roller 3102 (e.g.,agitator 204 of FIG. 2 ) configured to both agitate the target-vesselwall and infuse chemical agent 208 into the target vessel 202. Forinstance, FIG. 31A illustrates weeping roller 3102A while partiallysheathed within inner lumen 210 of elongated body 106. In some examples,weeping roller 3102A includes a dispersion tip defining a variablepattern (and/or sizes) of fluid apertures 810. Weeping roller 3102 canbe configured to either actively “spray” chemical agent 208 fromapertures 810, passively “weep” droplets of chemical agent 208 along thevessel wall, or a combination thereof.

Weeping roller 3102A may be attached to a distal end of inner member408, such as a shape-memory-material (e.g., Nitinol) hypotube, that bothdelivers chemical agent 208 into weeping roller 3102 and drives therotation of weeping roller 3102A about longitudinal axis 214. In somesuch examples, the inner member 408 is configured to assume apreconfigured shape once deployed from distal catheter mouth 510, asshown in FIGS. 31B and 31C.

For instance, FIG. 31B illustrates a radially offset roller 3102B,conceptually similar to radially offset hypotube 2702B of FIG. 27B. Thatis, inner member 408 is bent at an angle in order to offset roller 3102Bfrom central longitudinal axis 214 to improve contact with thetarget-vessel wall. In some such examples, ablation device 3114 definesa first axis of rotation (e.g., an axis of revolution) of inner memberabout central longitudinal axis 214, and a second axis of rotation ofroller 3102B about inner member 408. By comparison, FIG. 31C illustratesan axial roller 3102C configured to rotate only about longitudinal axis214. Such examples are useful for smaller-vessel applications withoutsufficient space for the off-axis rotation.

FIGS. 32A-32H are conceptual diagrams of a vessel occluder 3216 (e.g.,vessel occluder 216 of FIG. 2 ) having a bioabsorbable plug 3202A-3202H,respectively. During some existing surgical techniques, the clinicianinfuses a cyanoacrylate (or “cyano”) adhesive to embolize or occlude thetarget vessel 202. In accordance with techniques of this disclosure, theclinician may additionally or alternatively deploy vessel occluder 3216,including an at-least-partially bioabsorbable plug 3202, to performsimilar functions. In various examples described herein, plug 3202 caninclude any or all of an earplug-type mechanism (e.g., a compliantfoam), a suture-based plug, an adhesive-like filler (e.g., cyano), or adetachable, fluid-inflatable balloon plug made from suture material(e.g., PDS, etc.). For a balloon-type plug, the balloon can be“permanently” inflated (e.g., as compared to weeping balloon 910) withsaline or Polidocanol, and can remain within the target vessel 202postoperatively. In other words, the plug can include a “detachable”balloon configured to weep sclerosant both during and after theprocedure. As detailed further below, the plug can include a braidedsuture with a “skin” layer overtop, and/or a self-expanding stent thatis “sausage-tied” closed on either end.

For instance, FIG. 32A shows a stent-like, suture-material plug 3202Aconfigured to occlude the target vessel 202 (FIG. 2 ). The suturematerial of plug 3202A may be formed into a braided pattern, withproximal and distal ends sealed using a reflow process. In otherexamples, plug 3202A forms a full (e.g., fluid-tight) balloon.

FIG. 32B shows a self-expanding plug having both an outersuture-material layer 3204 and an inner bioabsorbable balloon 3206.Outer layer 3204 can be formed into a braided pattern, as describedabove. Inner balloon 3206 can be a weeping balloon (e.g., weepingballoon 910 of FIGS. 9C and 9D) and can remain within target vessel 202while inflated with chemical agent 208.

FIG. 32C is a conceptual diagram illustrating techniques for using abioabsorbable plug 3202C. Plug 3202C can include a braided,bioresorbable suture material with an occluded distal end. Additionallyor alternatively, plug 3202C can include a sponge-type thread, or ahydroscopic-gel thread. In some examples, plug 3202C includesbioresorbable coils similar to typical brain-occlusion coils for thetreatment of strokes.

In general, the clinician may use plug 3202C by navigating elongatedbody 106 (FIG. 1 ) to the target vessel within the patient 3208. Once inplace, the clinician deploys bioabsorbable plug 3202C from distalcatheter mouth 510 to occlude the target vessel and/or to secure theposition of plug 3202C within the patient's vasculature. Catheter 102may subsequently be withdrawn from the patient. The catheter is thenwithdrawn while laying out an expandable access thread 3210 from thebioabsorbable plug for subsequent plug removal, if necessary. Finally,the clinician may cut any excess proximal portion of thread 3210 andtuck it into the access site.

As shown in FIG. 32D, plug 3202D includes a braided “anchoring” stenthaving a distal fluid-tight covering 3212 configured to occlude bloodflow or the flow of other fluids (e.g., chemical agent 208 or otherdrugs) delivered to target vessel 202. By comparison, plug 3202E of FIG.32E includes a position-securement stent without having a distal cover,thereby permitting at least some fluid flow through the stent. Stent3214 can be used for temporary fixation, e.g., to anchor anothercomponent of ablation system 100, such as one of the balloons describedthroughout this disclosure, in place during the ablation treatment.

FIG. 32F shows a delivery system 3220 for a self-expanding, stent-likeplug 3202F. Delivery system 3220 includes a delivery-device tip 3218(e.g., ablation device 114 of FIG. 1 ) at a distal portion of elongatedbody 106. Elongated body 106 defines at least one fluid aperture 810 forinfusing a chemical agent 208 such as an occlusion fluid, a sclerosantfluid, or both. For instance, after initial occlusion by plug 3202F, anocclusion fluid (i.e., gel, cyanoacrylate, foam, etc.) may be infusedinto the target vessel 202 via aperture 810 to further support vesselocclusion.

FIGS. 32G and 32H illustrate example plugs 3202G, 3202H, respectively,having coiled structures 3222, as referenced above with respect to FIG.32C. In both FIGS. 32G and 32H, a bioresorbable-coil 3222 is shownpushing against the inner wall of target vessel 202. Plug 3202H of FIG.32H includes an additional stent 3224 for use in conjunction with thecoils 3222, which may facilitate securement of the coils 3222 withintarget vessel 202 and/or occlusion of target vessel 202.

Additionally or alternatively to infusing cyanoacrylate, the clinicianmay infuse a hydroscopic Polyvinylpyrrolidone (PVP) to absorb water inthe blood and swell to fill or occlude the target vessel 202. PVP can becrosslinked with Sodium Hydroxide (NaOH) to form a more resilient gel,mixed with a sclerosant, or mixed with fibrinogen concentrate to promoteblood clotting. Other potential fillers include hyaluronic acid (whichis naturally produced by human bodies and is already found in skin andcartilage), calcium hydroxyapatite (which is found in human bones),Poly-L-lactic acid (which is a biodegradable synthetic material used tomake other medical products, such as dissolvable stitches), andpolymethylmethacrylate beads (generally only used around the mouth).Fillers made with hyaluronic acid generally last between six and twelvemonths. Fillers made with calcium hydroxyapatite generally last up toeighteen months. Fillers made from Poly-L-lactic acid generally last upto two years. Fillers made from Polymethylmethacrylate beads cannot beabsorbed by the human body, and thus, results are generally permanent.

FIGS. 33A-33C are conceptual diagrams of vessel occluder 3316 (e.g.,vessel occluder 216 of FIG. 2 ) having a self-expanding basket3302A-3302C, respectively, configured to self-expand radially outward toretain chemical agent 208 within target vessel 202. In some examples,self-expanding basket 3302A includes a Nitinol “skirt” and shroud, aself-expanding braid or cut tubing, or a balloon. In some examples,self-expanding basket 3302A is coupled to inner member 408, such as astiff deployment wire or cable within the inner lumen 210. In someexamples, but not all examples, the self-expanding baskets 3302A-3302Care configured to rotate about longitudinal axis 214 to performmechanical agitation.

In the example shown in FIGS. 33B and 33C, self-expanding baskets 3302B,3302C include an outer fabric layer 3304A positioned overtop an innershape-memory-material layer 3304B. In some such examples, a distal tip3306 of inner member 408 may be atraumatic (e.g., rounded and/or formedfrom a compliant material). During use, the clinician infuses chemicalagent 208 through the inner lumen 210 of catheter 102 to wet the fabricof self-expanding basket 3302C while self-expanding basket 3302C issheathed within inner lumen 210. The clinician may then either retractelongated body 106, advance inner member 408, or both, to deploy theself-expanding basket 3302C from distal catheter mouth 510 and occludetarget vessel 202. Subsequently, the clinician may advance elongatedbody 106 distally forward, proximally retract inner member 408, or both,to retrieve the self-expanding basket 3302B, 3302C, e.g., to “re-wet”the fabric of the self-expanding basket 3302B, 3302C with chemical agent208.

FIGS. 34A-34F are conceptual diagrams of seven example ablation devices3414A-3414F (e.g., ablation device 114 of FIG. 1 ), each having arespective weeping balloon (e.g., weeping balloon 910 of FIGS. 9C and9D). For instance, FIG. 34A illustrates an example ablation device 3414Ahaving a shape-memory-material (e.g., Nitinol) “skirt” 3402 positionedproximal to weeping balloon 910. Shape-memory skirt 3402 may be anexample of self-expanding basket 3302A of FIG. 33A.

FIG. 34B illustrates an example ablation device 3414B having a radiallyexpanding shape-memory-material occluder 3304 positioned proximal toweeping balloon 910. Shape-memory occluder 3304 may function similar tocatheter wings 2502A of FIG. 25A.

FIG. 34C illustrates an example ablation device 3414C in which anexterior surface of weeping balloon 3410 includes a substantially roughor “spiked” texture configured to both abrade the vessel wall and helpretain balloon 910 in place via friction.

FIG. 34D illustrates an example ablation device 3414D with double-nestedweeping balloons 3406, 3408. Outer balloon 3406 includes a distalextension 3412 having a rough or spiked (or “diamond grip”) texture, asdescribed above with respect to FIG. 34C.

FIG. 34E illustrates an example ablation device 3414E having a proximalbrush 3416 (e.g., agitator 204 of FIG. 2 ), which may be an example ofbrushes 2602A-2602C of FIGS. 26A-26C.

FIG. 34F illustrates an example ablation device 3414F having aballoon-expandable agitator 3418 (e.g., agitator 204 of FIG. 2 ).Agitator 3418 defines an exterior surface having a cheese-grater-typemechanism, e.g., a plurality of radially misaligned convex and concaveportions defining vessel-abrading edges therebetween.

FIGS. 35A-35C are conceptual diagrams illustrating the functionality ofweeping balloon 910 of FIGS. 9C and 9D. For instance, FIG. 35Aillustrates weeping balloon 910 in its initial, uninflatedconfiguration. As shown in FIG. 35B, during use, the clinician may use afluid, such as chemical agent 208, to at least partially inflate balloon910 within target vessel 202. As shown in FIG. 35C, over time, the fluidbegins to weep or seep out from the microscopic pores defined by thesurface of the balloon. In particular, FIG. 35C illustrates chemicalagent 208 having a foaming property, configured to weep through theballoon pores and cover the exterior surface of the balloon. In somesuch examples, the clinician can manually generate this foam, e.g., byactuating a CO₂ mini-cartridge within control device 112. In someexamples, this foam can include a “cold” foam configured to ablatetarget vessel 202 via cryotherapy. In some examples, the foam can be“stabilized” through injection by air, carbon dioxide, nitrogen, orargon to extend the lifespan of the foam and accordingly, sclerosantuptake.

In some examples, weeping balloon 910 can be configured tosimultaneously perform three different functions: fluid infusion, viapores of the balloon; vessel occlusion, when pressurized and expandedagainst the target vessel wall; and mechanical vessel agitation. Forinstance, as referenced above, e.g., with respect to FIGS. 34C and 34F,an outer surface or outer layer of balloon 910 can include an abradingelement, such as a rough surface or cheese-grater-type mechanism.

In some examples, weeping balloon 910 may be semi-porous, permitting theinflation fluid to slowly perfuse directly into the wall of targetvessel 202 while weeping balloon 910 inflates. This would also allow theinflation fluid to exit along the entire longitudinal length of theweeping balloon 910 (as compared to just a proximal portion), therebyincreasing the area of treatment. In some examples, the internal fluidpressure within weeping balloon 910 reduces or prevents the inflationfluid from “washing out” of target vessel 202. In such examples, weepingballoon 910 may perform the occlusive functionality of vessel occluder216 of FIG. 2 . In some examples, weeping balloon 910 may be at leastpartially formed from an ethylene tetrafluoroethylene (ETFE) sleeve.

FIGS. 36A-36D are conceptual diagrams illustrating four example weepingballoons 3610A-3610D (e.g., weeping balloon 910 of FIGS. 9C and 9D),respectively.

FIG. 36A illustrates weeping balloon 3610A. Weeping balloon 3610Acomprises a polymer substrate 3602 (e.g., Pellethane™) coupled to ashape-memory-material basket 3604 (e.g., Nitinol). Basket 3604 may becoupled to either an exterior surface or the interior surface of thesubstrate, and is configured to cause balloon 3610A to self-expandradially outward, e.g., when advanced outward from distal catheter mouth510.

FIG. 36B illustrates weeping balloon 3610B. Weeping balloon 3610Bcomprises a polymer substrate 3602 disposed within a fabric sheath 3606,such as Nylon. Fabric sheath 3606 defines a plurality of weep holesconfigured to release chemical agent 208 into the surrounding tissue.

FIG. 36C illustrates weeping balloon 3610C. Weeping balloon 3610Ccomprises a plurality of molded anchors 3608. Molded anchors 3608 areconfigured to engage with the vessel wall to help retain balloon 3610Cin place within target vessel 202. Anchors 3608 can include anyhigh-friction shape and/or composition, such as polymer, fabric, ormetal hooks.

FIG. 36D illustrates weeping balloon 3610D. Weeping balloon 3610D is anexample of ablation device 2214 of FIG. 22 . That is, weeping balloon3610D includes a pair of proximal and distal compliant (e.g., flexible)anchorings 3612A, 3612B (e.g., balloons 2202A, 2202B of FIG. 22 ), witha semi-compliant (e.g., less-flexible) weeping section 3614therebetween. In another example, proximal and distal anchorings 3612are formed from a polymer (e.g., Pellethane™), and weeping section 3614may be formed from a fabric (e.g., Nylon).

FIG. 37 is a profile view of an ablation device 3714 (e.g., ablationdevice 114 of FIG. 1 ). As shown in FIG. 37 , ablation device 3714includes an agitator 3704 (e.g., agitator 204 of FIG. 2 ) having aplurality of elongated tines 506, and a weeping balloon 910. Inparticular, a proximal end of weeping balloon 910 is positioned radiallyinward from elongated tines 506, such that, when the clinician inflatesballoon 910 with an inflation fluid (e.g., chemical agent 208), theinflation of balloon 910 causes elongated tines 506 to expand radiallyoutward to contact the inner wall of target vessel 202.

FIG. 38 is a conceptual diagram of an ablation device 3814 (e.g.,ablation device 114 of FIG. 1 ) having an agitator 3804 (e.g., agitator204 of FIG. 2 ) and a compliant distal balloon 3810. A size (e.g., anamount of inflation) of balloon 3810 can be adjusted to a level ofencountered resistance between elongated tines 506 and the vessel wall.For instance, if excessive resistance is encountered, balloon 3810 canbe at least partially deflated to allow elongated tine to at leastpartially contract radially inward. After treatment, balloon 3810 may bedeflated and withdrawn from the patient's vasculature.

As shown in FIG. 38 , the proximal ends of elongated tines 506 arerigidly coupled to elongated body 106 are fixated on the catheter. Priorto inflation of balloon 3810, the distal ends of elongated tines may beencapsulated via a membrane or other retainer device, as described abovewith respect to FIGS. 9A-9D. Elongated tines 506 can be formed frommetal or plastic, and are not coupled to balloon 3810. Similar to theexample of FIG. 37 , elongated tines 506 expand radially outward towardthe wall of the target vessel 202 upon inflation of balloon 3810.

In some examples, catheter 102 includes a dual-lumen design, asdescribed above with respect to FIG. 4B, enabling direct infusion ofchemical agent 208. One or more fluid apertures to release chemicalagent 208 may be positioned just proximal to balloon 3810. For instance,after preparing (e.g., abrading) target vessel 202 (FIG. 2 ), theclinician may infuse chemical agent 208. In other examples, theclinician may infuse chemical agent 208 simultaneously with abradingtarget vessel 202.

FIG. 38 further illustrates the use of a modular rapid-exchange (“RX”)platform 3802, which itself may include an inflatable balloon. Ingeneral, RX platform 3802 enables the user to modify a size of an RXport 3806, e.g., via pullwire 3808. RX port 3806 (or “single-operatorexchange”) enables management of the guidewire (not shown) by theoperating clinician local to the access site, rather than by a separatesurgical technician positioned proximal to the ablation system.

Modular RX platform 3802 is configured to prepare certain lesions, asappropriate. Modular RX platform 3802 may be pre-loaded based onspecific clinical needs. For instance, for relatively easy-to-treatvessels, modular RX platform 3802 may not be necessary. For moredifficult applications, modular RX platform 3802 may be incorporatedinto ablation device 3814.

As a first non-limiting, illustrative example, the modular RX platform3802 can include a short-length balloon with a scoring wire (e.g.,elongated tines 506), and/or a sandpaper-like surface texture, asdescribed above with respect to FIG. 34C. In a second example, themodular RX platform 3802 can include a short-length balloon with a highpressure to break through tougher lesions. In a third example, themodular RX platform 3802 can include a short-length balloon thatincorporates both the scoring features and the high-pressure features.This short-length balloon may effectively treat tortuous anatomy,because the “straightening effect” exhibited by longer balloons isreduced, and RX platform 3802 would enable the balloon to be proximallyretracted in a controlled manner, while the compliant distal balloon3810 serves as an anchor and provides the necessary sealing functionthroughout the process.

FIGS. 39A and 39B are profile views of an example ablation device 3914(e.g., ablation device 114 of FIG. 1 ) having a distal interventionalballoon 3910. Distal balloon 3910 is an example of weeping balloon 910of FIGS. 9C and 9D, except for the differences noted herein.Specifically, as illustrated in FIGS. 39A and 39B, balloon 3910 definesa more-spherical shape, as compared to the more-elongated shape shown inFIGS. 9C and 9D.

As illustrated in FIGS. 39A and 39B, a distal portion of elongated body106 defines a fluid-aspiration port 3902. During use, the clinician mayuse fluid-aspiration port 3902 to evacuate a volume of the patient'sblood simultaneously with the infusion of chemical agent 208 to thetarget vessel 202. As described above with respect to FIG. 4C, atri-lumen elongated body 106 may be used to employ a guidewire, fluidinfusion, and fluid aspiration. Because there is less blood present inthe target vessel 202 after being evacuated, the chemical agent 208infused into the target vessel 202 will be less diluted. Accordingly, insuch examples, less chemical agent 208 may be needed for effectivevessel ablation. In some examples, a vacuum may be applied to the distalend of elongated body 106 to hold chemical agent 208 in place.

As shown in FIG. 39B, elongated body 106 defines fluid-infusion lumen410B running through the length of elongated body 106. Fluid-infusionlumen 410B may be configured to deliver chemical agent 208 to the targetvessel 202. The distal portion 110 of elongated body 106 defines atleast one opening enabling chemical agent 208 to exit fluid-infusionlumen 410B. In the example of FIG. 39B, fluid-infusion lumen 410B opensinto weeping balloon 3910 via fluid-inflation port 3904, allowing thefluid to inflate balloon 3910.

FIGS. 40A and 40B are conceptual diagrams of an example prototypeablation system 4000 (e.g., ablation system 100 of FIG. 1 ). As shown inFIG. 40A, ablation system 4000 includes a catheter 4002 (e.g., catheter102), a proximal syringe 4006 (e.g., fluid reservoir 206 of FIG. 2 ),and a distal ablation device 4014 (e.g., ablation device 114). As shownin FIG. 40B, ablation device 4014 includes an agitator having aplurality of elongated tines 4016 (e.g., tines 506 of FIG. 5 ), and aballoon 4010 disposed at least partially radially inward from tines4016. Balloon 4010 is configured to be inflated to cause tines 4016 toexpand radially outward, and pressurized to increase the contact forcebetween tines 4016 and the vessel wall.

A distal end of catheter 4002 defines at least one aperture 4022configured to infuse a sclerosant into the target vessel 202. Thesclerosant may be used both to inflate and pressurize balloon 4010, aswell as to chemically ablate the target vessel 202. In some examples,catheter 4002 may define multiple apertures 4022 of different sizes(e.g., diameters), forming a differential pressure within balloon 4010prior to vessel infusion.

FIGS. 41A-41D illustrate four examples of a “steerable” ablation device4114 (e.g., ablation device 114 of FIG. 1 ). In particular, ablationdevice 4114 includes a steerable distal portion 4110 (e.g., distalportion 110 of FIG. 1 ) of elongated body 106. FIG. 41A illustratesdistal portion 4110 in a linear configuration, e.g., conformingsubstantially to longitudinal axis 214. As described above with respectto FIG. 4B, distal portion 4110 defines guidewire lumen 410A andfluid-infusion lumen 410B.

As illustrated in FIG. 41B, the clinician may actuate a pullwire 4112,e.g., positioned within guidewire lumen 410A, to deflect distal portion4110 away from longitudinal axis 214 by a variable angle θ, asappropriate. As further shown in FIG. 41B, distal portion 4110 isconfigured to optionally infuse chemical agent 208, via fluid-infusionlumen 410B, from distal catheter mouth 510. Additionally oralternatively, the exterior surface of distal portion 4110 defines aplurality of fluid apertures 810 of varying size and/or arrangement,enabling the user to optionally infuse chemical agent 208 via apertures2204. Finally, as shown in FIG. 41D, the clinician may actuate usercontrol 212 to cause distal portion 4110 to rotate about longitudinalaxis 214, thereby dispersing chemical agent 208 around the interiorsurface of vessel wall.

FIGS. 42A-42C are conceptual diagrams illustrating a technique for usingtwo interventional balloons 4210A, 4210B (or other expandablestructures) of ablation device 114 of FIG. 1 to straighten target vessel202 prior to ablation. As shown in FIGS. 42A-42C, proximal and distalballoons 4210A, 4210B may be independently operated to position theballoons within the target vessel (FIG. 42A), and then inflated so as toengage with the wall of the target vessel 202 (FIG. 42B). Thelongitudinal positions of balloons 4210 may further be manipulated toincrease the longitudinal distance between proximal and distal balloons4210, thereby causing the vessel region between balloons 4210 tostraighten and/or narrow. As shown in FIG. 42C, chemical agent 208 maythen be infused into the vessel region between balloons 4210 to ablatethe surrounding tissue.

In some examples, the steps of this technique may be reversed in orderto longitudinally compress the vessel region between balloons 4210. Inthis way, the target vessel 202 may be cyclically stretched andcompressed, e.g., in order to mechanically ablate the vessel obstructionor to induce a vessel spasm, as appropriate.

FIG. 43 is a conceptual diagram illustrating an example ablation device4314 (e.g., ablation device 114 of FIG. 1 ) having a radially eccentricballoon 4310. Balloon 4310 is configured to inflate to radially offsetelongated body 106 to compress fluid apertures 810 against the vesselwall for more-direct infusion of chemical agent 208.

In the example shown in FIG. 43 , ablation device 4314 includes a singleeccentric balloon 4310 positioned along one side of the exterior surfaceof elongated body 106. The opposite side of the exterior surface ofelongated body 106 defines fluid apertures 810. Once the clinician hasfluid-inflated balloon 4310 to compress apertures 810 near or againstvessel wall, the clinician may then rotate ablation device 4314 aboutlongitudinal axis 214 so as to infuse chemical agent 208 around theentire inner circumference of vessel wall.

In other examples, ablation device 4314 may include a plurality ofindependently inflatable balloons 4310, and a respective plurality offluid apertures 810, distributed around the outer circumference ofelongated body 106. During use, the clinician may selectively inflateand deflate each of the balloons 4310 to radially deflect the elongatedbody along different directions and treat different portions of theinner circumference of the vessel wall, e.g., in addition to, or insteadof, rotating ablation device 4314.

FIG. 44 is a conceptual diagram illustrating an example ablation device4414 (e.g., ablation device 114 of FIG. 1 ) having a self-expandingballoon 4410. Balloon 4410 is an example of balloon 3610A of FIG. 36A.That is, balloon 4410 includes a self-expanding (e.g.,shape-memory-material) basket 4402 (3604) disposed within the interiorsurface (3602) of the balloon 4410. In response to advancing outwardfrom distal mouth 510 of catheter 102 (or equivalently, of introducersheath 104), basket 4402 is configured to automatically assume itspreviously set shape, causing balloon 4410 to expand radially outwardwithout requiring separate inflation, e.g., fluid-inflation.

In examples in which balloon 4410 comprises a porous or semi-porousballoon (e.g., weeping balloon 910 of FIGS. 9C and 9D), chemical agent208 may be injected through fluid-infusion lumen 410B (FIG. 4B) and intoballoon 4410 for subsequent vessel infusion. Such examples may helpcontrol a precise amount and/or rate of chemical agent 208 infused intovessel wall.

In examples in which balloon 4410 includes a non-porous balloon,chemical agent 208 can be infused from distal catheter mouth 510 andthen “wicked” around the exterior surface of balloon 4410. Such examplesmay help reduce or prevent excess chemical agent 208 from traveling“upstream” past balloon 4410.

FIGS. 45A-45C are conceptual diagrams illustrating an example techniquefor mechanically ablating a target vessel 202. Additionally oralternatively to a rotational agitator as described in previous examples(e.g., agitator 204 of FIG. 2 ), in the example of FIGS. 45A-45C,ablation device 4514 (e.g., ablation device 114 of FIG. 1 ) includes avessel agitator in the form of a needle 4502 deployed from distalcatheter mouth 510 (FIG. 45A). Needle 4502 is configured to stitch athread or suture through target vessel wall(s) at multiple locations(FIG. 45B). Needle 4502 may then be withdrawn back through cathetermouth 510, and the suture may be pulled tight to collapse the targetvessel 202 radially and/or longitudinally inward on itself (FIG. 45C).

Additionally or alternatively, the clinician may deploy a “reverse”stent configured to expand radially outward and rigidly anchor to thetarget vessel 202. Upon removal of the delivery system, the reversestent will collapse the vein inward on itself.

FIG. 46 is a flow chart illustrating a technique for ablating a targetvessel 202 (FIG. 2 ), such as a varicose vein. The technique may includeinserting a catheter 102 (FIG. 1 ) into a vasculature of a patient (atstep 4600). The technique further includes advancing the catheter 102 tothe target vessel 202 (at step 4602), and actuating a user control 212on control device 112 operatively coupled to a proximal portion 108 ofthe catheter 102 (at step 4604). The control device 112 longitudinallytranslates a distal ablation device 114 through the target vessel 202(at step 4606), and simultaneously infuses a chemical agent 208 into thetarget vessel (at step 4608). Additionally or alternatively, the controldevice 112 actuates a motion, such as a rotation, vibration, oroscillation, of a mechanical agitator 204.

Interpretation

None of the steps described herein is essential or indispensable. Any ofthe steps can be adjusted or modified. Other or additional steps can beused. Any portion of any of the steps, processes, structures, and/ordevices disclosed or illustrated in one embodiment, flowchart, orexample in this specification can be combined or used with or instead ofany other portion of any of the steps, processes, structures, and/ordevices disclosed or illustrated in a different embodiment, flowchart,or example. The embodiments and examples provided herein are notintended to be discrete and separate from each other.

The section headings and subheadings provided herein are nonlimiting.The section headings and subheadings do not represent or limit the fullscope of the embodiments described in the sections to which the headingsand subheadings pertain. For example, a section titled “Topic 1” mayinclude embodiments that do not pertain to Topic 1, and embodimentsdescribed in other sections may apply to and be combined withembodiments described within the “Topic 1” section.

To increase the clarity of various features, other features are notlabeled in each figure.

The various features and processes described above may be usedindependently of one another or may be combined in various ways. Allpossible combinations and subcombinations are intended to fall withinthe scope of this disclosure. In addition, certain method, event, state,or process blocks may be omitted in some implementations. The methods,steps, and processes described herein are also not limited to anyparticular sequence, and the blocks, steps, or states relating theretocan be performed in other sequences that are appropriate. For example,described tasks or events may be performed in an order other than theorder specifically disclosed. Multiple steps may be combined in a singleblock or state. The example tasks or events may be performed in serial,parallel, or some other manner. Tasks or events may be added to orremoved from the disclosed example embodiments. The example systems andcomponents described herein may be configured differently thandescribed. For example, elements may be added to, removed from, orrearranged compared to the disclosed example embodiments.

Conditional language used herein, such as, among others, “can,” “could,”“might,” “may,” “e.g.,” and the like, unless expressly stated otherwise,or otherwise understood within the context as used, is generallyintended to convey that certain embodiments include, while otherembodiments do not include, certain features, elements and/or steps.Thus, such conditional language is not generally intended to imply thatfeatures, elements, and/or steps are in any way required for one or moreembodiments or that one or more embodiments necessarily include logicfor deciding, with or without author input or prompting, whether thesefeatures, elements and/or steps are included or are to be performed inany particular embodiment. The terms “comprising,” “including,”“having,” and the like are synonymous and are used inclusively, in anopen-ended fashion, and do not exclude additional elements, features,acts, operations, and so forth. Also, the term “or” is used in itsinclusive sense (and not in its exclusive sense) so that when used, forexample, to connect a list of elements, the term “or” means one, some,or all of the elements in the list. Conjunctive language such as thephrase “at least one of X, Y, and Z,” unless expressly stated otherwise,is otherwise understood with the context as used in general to conveythat an item, term, etc. may be either X, Y, or Z. Thus, suchconjunctive language is not generally intended to imply that certainembodiments require at least one of X, at least one of Y, and at leastone of Z to each be present.

The term “and/or” means that “and” applies to some embodiments and “or”applies to some embodiments. Thus, A, B, and/or C can be replaced withA, B, and C written in one sentence and A, B, or C written in anothersentence. A, B, and/or C means that some embodiments can include A andB, some embodiments can include A and C, some embodiments can include Band C, some embodiments can only include A, some embodiments can includeonly B, some embodiments can include only C, and some embodiments caninclude A, B, and C. The term “and/or” is used to avoid unnecessaryredundancy.

While certain example embodiments have been described, these embodimentshave been presented by way of example only and are not intended to limitthe scope of the inventions disclosed herein. Thus, nothing in theforegoing description implies that any particular feature,characteristic, step, module, or block is necessary or indispensable.Indeed, the novel methods and systems described herein may be embodiedin a variety of other forms; furthermore, various omissions,substitutions, and changes in the form of the methods and systemsdescribed herein may be made without departing from the spirit of theinventions disclosed herein.

What is claimed is:
 1. A vein ablation system, comprising: a catheterhaving an elongated body; an ablation device at a distal portion of theelongated body; and a control device at a proximal portion of theelongated body, the control device comprising: an input mechanismconfigured to simultaneously control: an infusion of a chemical agentinto a target vessel; a longitudinal translation of the ablation devicethrough the target vessel; and a dual coaxial worm gear comprising afirst worm gear configured to drive the longitudinal translation and asecond worm gear configured to infuse the chemical agent.
 2. The veinablation system of claim 1, wherein the second worm gear functions as anArchimedes screw, the Archimedes screw configured to distally pump thechemical agent toward the target vessel.
 3. The vein ablation system ofclaim 1, wherein the input mechanism is configured to control a rate ofthe infusion of the chemical agent relative to a distance of thelongitudinal translation of the ablation device.
 4. The vein ablationsystem of claim 1, further comprising a porous balloon configured torelease the chemical agent.
 5. The vein ablation system of claim 4,wherein the porous balloon is disposed at the distal portion of theelongated body of the catheter.
 6. The vein ablation system of claim 1,wherein the ablation device defines a sinusoidal shape, and wherein theablation device is configured to rotate about a central longitudinalaxis.
 7. The vein ablation system of claim 6, wherein the ablationdevice defines a plurality of pores configured to release the chemicalagent.
 8. The vein ablation system of claim 6, further comprising aninterventional balloon retaining the sinusoidal shaped ablation device.9. The vein ablation system of claim 8, wherein the interventionalballoon includes a porous membrane configured to release the chemicalagent.
 10. The vein ablation system of claim 9, wherein the sinusoidalshaped ablation device is configured to rotate to infuse the chemicalagent through the porous membrane of the interventional balloon.
 11. Thevein ablation system of claim 6, wherein a distal portion of theablation device comprises a spherical tip.
 12. The vein ablation systemof claim 11, wherein the spherical tip is configured to increase anapplied pressure against a vessel wall.
 13. The vein ablation system ofclaim 6, further comprising a motor operatively coupled to the ablationdevice and configured to rotate the ablation device when power issupplied to the motor.
 14. The vein ablation system of claim 1, whereinthe input mechanism is further configured to control a movement selectedfrom the group consisting of rotation, vibration, and agitation of theablation device about a central longitudinal axis.
 15. The vein ablationsystem of claim 14, wherein the input mechanism is configured tosimultaneously control the longitudinal translation and the rotation ofthe ablation device.
 16. The vein ablation system of claim 14, whereinthe input mechanism is configured to control a rate of the infusion ofthe chemical agent relative to the movement of the ablation device aboutthe central longitudinal axis.
 17. The vein ablation system of claim 16,wherein the input mechanism is configured to control the rate of theinfusion of the chemical agent relative to a number of rotations of theablation device.
 18. The vein ablation system of claim 1, wherein thechemical agent comprises a sclerosant.
 19. The vein ablation system ofclaim 18, further comprising a foaming agent cartridge detachablycoupled to the control device.
 20. The vein ablation system of claim 19,wherein the foaming agent cartridge is arranged and configured torelease a foaming agent to create a foam when mixed with the sclerosant.